T.O. 33B-1-2 (Rev) Technical Manual PDF

T.O. 33B-1-2 TECHNICAL MANUAL NONDESTRUCTIVE INSPECTION GENERAL PROCEDURES AND PROCESS CONTROLS...

T.O. 33B-1-2 TECHNICAL MANUAL NONDESTRUCTIVE INSPECTION GENERAL PROCEDURES AND PROCESS CONTROLS (ATOS) DISTRIBUTION STATEMENT C: Distribution authorized to U.S. Government agencies and their contractors, Administrative or Operational Use, 31 August 1986. Refer other requests for this document to AFRL/MLS-OL, Tinker AFB, Oklahoma 73145-3317. WARNING: This document contains technical data whose export is restricted by the Arms Export Control Act (Title 22, U.S.C. 2751 et seq.) or the Export Administration Act of 1979, as amended, Title 50, U.S.C., App. 2401, et seq. Violation of these export-control laws is subject to severe criminal penalties. Dissemination of this document is controlled under DoD Directive 5230.25. HANDLING AND DESTRUCTION NOTICE: Destroy by any method that will prevent disclosure of contents or reconstruction of the document. Published under the authority of the Secretary of the Air Force 1 JUNE 2006 T.O. 33B-1-2 INSERT LATEST CHANGED PAGES. DESTROY SUPERSEDED PAGES. LIST OF EFFECTIVE PAGES NOTE: The portion of the text affected by the changes is indicated by a vertical line in the outer margins of the page. Changes to illustrations are indicated by miniature pointing hands. Changes to wiring diagrams are indicated by shaded areas. Dates of issue for original and changed pages are: Original.................... 0............... 1 June 2006 TOTAL NUMBER OF PAGES IN THIS MANUAL IS 138, CONSISTING OF THE FOLLOWING: Page *Change Page *Change Page *Change No. No. No. No. No. No. Title......................... 0 A............................ 0 i - v.......................... 0 vi Blank...................... 0 vii........................... 0 viii Blank.................... 0 ix - xi........................ 0 xii Blank..................... 0 1-1 - 1-4..................... 0 2-1 - 2-17.................... 0 2-18 Blank................... 0 3-1 - 3-20.................... 0 4-1 - 4-59.................... 0 4-60 Blank................... 0 5-1 - 5-18.................... 0 6-1 - 6-3..................... 0 6-4 Blank.................... 0 *Zero in this column indicates an original page A USAF  T.O. 33B-1-2 TABLE OF CONTENTS Chapter Page Chapter Page INTRODUCTION......................................................vii 2.2.1 Equipment and Materials Re- quired for Cracked-Chrome Panel Test...............................................2-8 SAFETY SUMMARY................................................ix 2.2.2 Procedure for Cracked-Chrome Panel Test...............................................2-8 2.2.3 Testing for Failed Penetrant.......................2-9 1 NONDESTRUCTIVE INSPECTION 2.2.4 Testing for Failed Emulsifier/Re- METHODS, GENERAL INFORMA- mover.....................................................2-9 TION.....................................................................1-1 2.2.5 Testing for Failed Developer.....................2-9 2.2.6 Lipophilic Penetrant Systems.....................2-9 2.2.7 Water Washable Penetrant Sys- SECTION I INTRODUCTION..............................1-1 tems........................................................2-9 2.2.8 Solvent Removable Penetrant Sys- 1.1 Introduction.................................................1-1 tems........................................................2-9 1.1.1 Purpose........................................................1-1 2.3 System Performance Test with the 1.1.2 Scope...........................................................1-1 PSM Starburst Panel (Depot 1.1.3 Format of Procedures.................................1-1 Only)......................................................2-9 1.1.4 Knowledge of NDI.....................................1-1 2.3.1 Procedure for Performing the 1.1.5 NDI Points-of-Contact................................1-1 PSM Starburst Panel Test....................2-10 SECTION II PROCESS CONTROLS...................1-3 2.3.2 Response of PSM Panels.........................2-10 2.3.3 Reading PSM Starburst Indica- 1.2 Process Controls.........................................1-3 tions......................................................2-10 1.2.1 Reason for Controlling the Pro- 2.3.4 Cleaning PSM Panels...............................2-11 cess.........................................................1-3 2.4 Inspection Booth Checks..........................2-11 1.2.2 Scope of Process Control...........................1-3 2.5 Surface Wetting Test................................2-11 2.6 Penetrant Brightness Test - (DE- 2 FLUORESCENT LIQUID PENETRANT POT ONLY)........................................2-11 INSPECTION.......................................................2-1 2.6.1 Penetrant Rapid Brightness Test (FIELD LABS)....................................2-12 2.7 Testing Concentration of Water SECTION I FLUORESCENT LIQUID Based (Method ‘‘A’’) Pene- PENETRANT INSPECTION GENER- trants.....................................................2-12 AL PROCEDURE................................................2-1 2.8 Testing Lipophilic Emulsifier (Method ‘‘B’’).....................................2-12 2.1 Fluorescent Liquid Penetrant In- 2.8.1 Lipophilic Emulsifier Removabili- spection General Procedure...................2-1 ty Test..................................................2-13 2.1.1 Preparation of Part......................................2-1 2.9 Hydrophilic Remover Refractome- 2.1.2 Penetrant Application Procedure................2-2 ter Test.................................................2-13 2.1.3 Penetrant Removal Procedure....................2-3 2.9.1 Hydrophilic Remover Hydrometer 2.1.4 Developer Application and Drying Test.......................................................2-14 Procedure...............................................2-4 2.9.2 Hydrophilic Remover Quick Test 2.1.5 Fluorescent Penetrant Interpreta- for Penetrant Contamination................2-14 tion.........................................................2-6 2.9.3 Hydrophilic Remover Perform- 2.1.6 Bleed-Back Method....................................2-7 ance Check...........................................2-14 2.1.7 Post Cleaning..............................................2-7 2.9.4 Hydrophilic Remover Background Fluorescence Check.............................2-14 SECTION II FLUORESCENT LIQUID 2.9.5 Hydrophilic Remover Spray Solu- PENETRANT INSPECTION PRO- tion Test...............................................2-15 CESS CONTROL................................................2-8 2.10 Water-Suspended Developer Con- centration Test......................................2-15 2.2 System Performance Test Proce- dure - Cracked-Chrome Panels............2-8 i T.O. 33B-1-2 2.10.1 Water-Suspended (or Soluble) De- 3.2.9 Vehicle Fluorescence Check....................3-20 veloper Coating Uniformity 3.2.10 Acidity Test..............................................3-20 Test.......................................................2-16 3.2.11 Water Break Test......................................3-20 2.10.2 Water-Suspended (or Soluble) De- 3.2.12 Field Indicator Check...............................3-20 veloper Penetrant Contamina- tion Test...............................................2-16 4 EDDY CURRENT INSPECTION...........................4-1 2.10.3 Water-Soluble Developer Concen- tration Test...........................................2-16 2.10.4 Dry Developer Contamination SECTION I EDDY CURRENT INSPEC- Test.......................................................2-16 TION GENERAL PROCEDURE.......................4-1 2.11 Cleaning Procedure for Process Control Test Panels..............................2-17 4.1 Eddy Current General Procedure...............4-1 2.12 Water Pressure and Temperature 4.1.1 Approved Equipment..................................4-1 Check...................................................2-17 4.1.2 Eddy Current Scanning Tech- niques.....................................................4-5 3 FLUORESCENT MAGNETIC PARTICLE 4.1.3 General Eddy Current Inspection INSPECTION.......................................................3-1 Procedures............................................4-10 SECTION II EDDY CURRENT PRO- SECTION I FLUORESCENT MAGNET- CESS CONTROL PROCEDURES...................4-56 IC PARTICLE INSPECTION GENER- AL PROCEDURE................................................3-1 4.2 Eddy Current Process Control Procedures............................................4-56 3.1 General Magnetic Particle Proce- 4.2.1 General Process Control for Eddy dures.......................................................3-1 Current Inspection Probes and 3.1.1 Required Equipment and Materi- Standards..............................................4-56 als...........................................................3-1 4.2.2 Probe Test.................................................4-56 3.1.2 Preparation of Part......................................3-1 4.2.3 Slot Test....................................................4-57 3.1.3 Selecting Type of Magnetizing Current...................................................3-2 5 ULTRASONIC INSPECTION.................................5-1 3.1.4 Longitudinal Magnetization (Coil Shots).....................................................3-2 SECTION I ULTRASONIC INSPEC- 3.1.5 Longitudinal Magnetism Induced TION GENERAL PROCEDURE.......................5-1 by Portable Yokes..................................3-6 3.1.6 Circular Magnetism Produced by Direct Contact........................................3-7 SECTION II ULTRASONIC INSPEC- 3.1.7 Demagnetizing Test Parts.........................3-11 TION PROCESS CONTROL..............................5-2 3.1.8 Post-Cleaning Test Parts After Magnetic Particle Inspection...............3-12 5.1 Ultrasonic Inspection Process 3.1.9 QQI Shims................................................3-12 Control...................................................5-2 3.1.10 Magnetic Particle Inspection Inter- 5.1.1 Procedure for Determining Verti- pretation...............................................3-12 cal Linearity Limits (ASTM Blocks)...................................................5-2 SECTION II FLUORESCENT MAG- 5.1.2 Procedure for Determining Hori- NETIC PARTICLE PROCESS CON- zontal Linearity Limits (Type 2 TROL PROCEDURES......................................3-14 IIW Block).............................................5-3 5.1.3 Procedure for Determining Inspec- 3.2 System Effectiveness Check tion System Sensitivity (ASTM (Ketos Ring).........................................3-14 Blocks)...................................................5-4 3.2.1 Quantitative Quality Indicators 5.1.4 Checking Resolution (Type 2 IIW (QQI)....................................................3-15 Block).....................................................5-5 3.2.2 Cracked Parts............................................3-16 5.1.5 A-Scan Straight Beam Distance 3.2.3 Amperage Indicator Check.......................3-16 Calibration..............................................5-8 3.2.4 Quick Break Test......................................3-16 5.1.6 Angle Beam Distance Calibration 3.2.5 Dead Weight Check.................................3-17 (Type 2 IIW Block).............................5-11 3.2.6 UV-A Black Light Intensity and 5.1.7 Angle Beam Point-of-Incidence Ambient Light Requirements..............3-17 (Type 2 IIW Block).............................5-14 3.2.7 Fluorescent Background Check 5.1.8 Determining Angle Beam Mis- for New Bulk Suspension....................3-18 alignment (Skew Angle)......................5-16 3.2.8 Particle Concentration Test......................3-18 ii  T.O. 33B-1-2 5.1.9 Angle Beam Angle Determination (Type 2 IIW Block).............................5-17 6.1 Radiographic Inspection Process Control...................................................6-2 6 RADIOGRAPHIC INSPECTION............................6-1 6.1.1 Individual Safelight Evaluation Check.....................................................6-2 6.1.2 Collective Safelight Check.........................6-2 SECTION I RADIOGRAPHIC INSPEC- 6.1.3 Developer Testing.......................................6-2 TION GENERAL PROCEDURE.......................6-1 6.1.4 Fixer Control...............................................6-3 6.1.5 Safelight Filter Check.................................6-3 6.1.6 Interlock Operational Check......................6-3 SECTION II RADIOGRAPHIC INSPEC- 6.1.7 Survey Meter Operational Check...............6-3 TION GENERAL PROCEDURE.......................6-2 LIST OF ILLUSTRATIONS Number Title Page Number Title Page 3-1 Longitudinal Magnetization in a Coil............ 3-2 4-13 Impedance Plane Response (with High 3-2 Magnetic Field Produced by a Portable Pass Filter) from the 0.005 Inch Yoke........................................................... 3-7 Notch (4340 Steel) with Acceptable 3-3 Circular Magnetic Field Produced by Signal-To-Noise....................................... 4-21 Direct Contact............................................ 3-8 4-14 Typical Lift-off Response with Phase 3-4 Circular Magnetism Using a CBC................. 3-9 Adjusted Correctly................................... 4-25 3-5 Circular Magnetism Using a CBC on 4-15 Impedance Plane Display............................. 4-26 Ring-Shaped Parts.................................... 3-10 4-16 Properly Calibrated Sweep Display............. 4-26 3-6 Quantitative Quality Indicators (QQI)......... 3-12 4-17 Acceptable Noise Level from Clean 3-7 Ketos Ring.................................................... 3-15 Hole.......................................................... 4-27 3-8 Black Light Intensity.................................... 3-17 4-18 30% PTP Signal Requires Evaluation.......... 4-27 3-9 Centrifuge Tube............................................ 3-19 4-19 Establishing Sync Zero Position of the 4-1 Eddy Current Reference Standard.................. 4-3 Nortec Spitfire Scanner............................ 4-29 4-2 Alternate Surface Eddy Current Refer- 4-20 Establishing Sync Zero Position of the ence Standard............................................. 4-5 Nortec Minimite Scanner......................... 4-30 4-3 Required Scanning Directions........................ 4-7 4-21 Establishing Top, Center Scanner Zero 4-4 Scanning Around Fastener with Flush Position (Method B)................................. 4-30 Heads.......................................................... 4-8 4-22 Sweep Display with Alarm Gates................ 4-31 4-5 Scanning Around Fastener with Pro- 4-23 Impedance Plane Display with Alarm truding Heads............................................. 4-9 Gates......................................................... 4-32 4-6 Scanning Radii................................................ 4-9 4-24 Split Screen Display with Sweep Dis- 4-7 Signal Response from 0.020 inch Deep play Alarm Gates and Impedance Notch in Aluminum................................. 4-13 Plane Display Lift-off Limits.................. 4-33 4-8 Responses from 0.005, 0.010, and 0.020 4-25 Example of Crack Indication in Hole inch Deep Notches (Aluminum) with with Noise Level Greater than Acceptable Signal-to-Noise..................... 4-14 30%Fsw.................................................... 4-34 4-9 Indication Exceeding 10% Vertical De- 4-26 Example of Excessive Noise in the flection...................................................... 4-15 Sweep Mode (Left) and in the Impe- 4-10 80% FSH Signal from a 0.020 Inch dance Plane Mode (Right)....................... 4-34 Deep Notch............................................... 4-18 4-27 Lift-off Response with Phase Adjusted 4-11 Impedance Plane Display of 80% Ptp Correctly................................................... 4-38 Signal from the 0.020 Inch Deep 4-28 Idealized Response Illustrating Mini- Notch........................................................ 4-19 mum Separation Between Lift-off 4-12 Impedance Plane Response (without and EDM Notch Response...................... 4-39 High Pass Filter) from the 0.005 4-29 Properly Calibrated Sweep Display Inch Notch (4340 Steel) with Ac- (Steel)....................................................... 4-40 ceptable Signal-To-Noise......................... 4-20 iii T.O. 33B-1-2 4-30 Acceptable Noise Level from Clean 5-1 Use the Type 2 IIW Block to Check Hole (Steel).............................................. 4-40 Horizontal Linearity................................... 5-3 4-31 Signal from Hole Subject to Evaluation 5-2 Use Type 2 IIW Block to Check Back (Steel)....................................................... 4-41 Surface Resolution..................................... 5-5 4-32 SYNC Zero Position of the Nortec Spit- 5-3 Use a Type 2 IIW Block to Check En- fire Scanner (Steel).................................. 4-43 try Surface Resolution............................... 5-7 4-33 SYNC Zero Position of the Nortec 5-4 Straight Beam Distance Calibration MiniMite Scanner (Steel)......................... 4-44 with IIW Block........................................ 5-10 4-34 SYNC Zero Position (Method B) 5-5 Straight Beam Distance with Miniature (Steel)....................................................... 4-44 Angle Beam Block................................... 5-11 4-35 Response from 0.030 Inch Interface 5-6 Angle Beam Distance Calibration with Notch with Phase at a 45 Degree IIW Block................................................. 5-13 Angle........................................................ 4-49 5-7 Angle Beam Distance Calibration with 4-36 Example of Properly Calibrated Sweep Miniature Angle Beam Block.................. 5-14 Display (Titanium)................................... 4-49 5-8 Point of Incidence Determination with 4-37 Example of Acceptable Noise Level IIW Block................................................. 5-15 from Clean Hole. Noise Level Shall 5-9 Point of Incidence Determination with Not Exceed 10% FSH from Baseline..... 4-50 Miniature Angle Beam Block.................. 5-16 4-38 Display of Signal from Hole That is 5-10 Beam Misalignment (Skew Angle).............. 5-16 Subject to Evaluation (Titanium)............ 4-50 5-11 Skew Angle Measurement............................ 5-17 4-39 Establishing SYNC Zero Position of the 5-12 Angle Determination with Type 2 IIW Nortec Spitfire Scanner (Titanium)......... 4-52 Block......................................................... 5-18 4-40 Establishing SYNC Zero Position of the 5-13 Angle Determination with Miniature Nortec MiniMite Scanner (Titanium)..... 4-53 Angle Beam Block................................... 5-18 4-41 Establishing SYNC Zero Position of the Nortec Spitfire Scanner (Method C)....... 4-53 LIST OF TABLES Number Title Page Number Title Page 1-1 Frequency for Process Control......................... 1-3 4-6 Settings Prior to Calibration for Surface 2-1 Fluorescent Penetrant Advantages and Scanning of Steel Parts.............................. 4-16 Limitations.................................................... 2-1 4-7 Nortec 2000D Calibration Settings Scan- 2-2 Material and Minimum Penetrant Sensi- ning of Aluminum Fastener Holes............ 4-23 tivity Level................................................... 2-2 4-8 Frequency Settings Fastener Hole Scan- 2-3 Penetrant Dwell Times...................................... 2-3 ning of Aluminum, Non-Ferrous Al- 2-4 Developer Dwell Times.................................... 2-5 loys, and Weakly Ferromagnetic 3-1 Fluorescent Magnetic Particle Advan- Alloys.......................................................... 4-24 tages and Limitations................................... 3-1 4-9 Filter Settings vs. Hole Diameter................... 4-24 3-2 Coil Size vs. Maximum Part Diameter 4-10 Sweep Display Alarm Gate Settings.............. 4-31 for Bottom of Coil Shot............................... 3-3 4-11 Impedance Plane Display Alarm Gate 3-3 Typical Current for Five-Turn Coil with Settings....................................................... 4-31 Part at the Bottom of Coil........................... 3-4 4-12 Settings Prior to Calibration of Nortec 3-4 Ring Specimen Indications............................. 3-15 2000D/2000D+ Fastener Hole Scan- 3-5 Empirical Black Light Intensity Require- ning of Magnetic Steel Parts..................... 4-36 ments at Various Ambient Light 4-13 Filter Settings vs. Hole Diameter................... 4-37 Levels for Portable Inspections................. 3-18 4-14 Nortec 2000D Initial Calibration Settings 4-1 Reference Standard Materials........................... 4-2 for Rotary Scanning of Fastener Holes 4-2 Nortec 2000D Initial Settings for Deter- in Titanium Parts........................................ 4-47 mining Lift-off Compensation..................... 4-6 4-15 (Titanium) Filter Settings vs. Hole Diam- 4-3 Nortec 2000D Inspection Frequencies by eter.............................................................. 4-47 Material......................................................... 4-7 5-1 Vertical Linearity.............................................. 5-2 4-4 Nortec 2000D Settings for Surface Scan 5-2 Horizontal Linearity.......................................... 5-3 of Aluminum.............................................. 4-11 5-3 Minimum Sensitivity Requirements................. 5-4 4-5 Nortec 2000D Inspection Frequencies........... 4-12 5-4 Resolution Set-up.............................................. 5-5 iv  T.O. 33B-1-2 5-5 Dead Zone Set-up............................................. 5-7 5-8 Straight Beam Distance.................................. 5-10 5-6 Limits of Boundary Surface Resolution........... 5-8 5-9 Auto Calibration Procedures........................... 5-12 5-7 Auto Calibration Procedures............................. 5-8 5-10 Angle Beam Distance Calibration.................. 5-13 v/(vi blank)  T.O. 33B-1-2 INTRODUCTION 1. PURPOSE. This manual provides information necessary for operating and maintaining the Non Destructive Inspection general procedures and process controls. 2. IMPROVEMENT REPORTS. Recommendations for improvements to this technical order will be submitted on AFTO Form 22, Publication Change Request, in accordance with TO 00-5-1. Complete forms will be forwarded to 448 MSUG/GBMUH, Tinker AFB, OK 73145. vii/(viii Blank)  T.O. 33B-1-2 SAFETY SUMMARY 1. GENERAL SAFETY INSTRUCTIONS. The following are general safety precautions and instructions individuals must understand and apply during many phases of operation and maintenance to ensure personal safety, health, and the protection of Air Force property. Portions of this may be repeated elsewhere in this publication for emphasis. Additional safety precautions are contained in AFOSH STD 91-110, AFOSH STD 91-501, and Army: AR 385-10 paragraph 1. 2. SHALL, SHOULD, MAY, AND WILL. Use the word ‘‘SHALL’’ whenever a manual expresses a provision that is binding. Use ‘‘SHOULD’’ and ‘‘MAY’’ whenever it is necessary to express non-mandatory provisions. ‘‘WILL’’ may be used to express a declaration purpose. It may be necessary to use ‘‘WILL’’ in cases where simple futurity is required (e.g., ‘‘Power for the meter WILL be supplied by the ship’’). 3. WARNINGS, CAUTIONS, AND NOTES. WARNING This highlights an essential operating or maintenance procedure, practice, condition statement, etc., which if not strictly observed, could result in injury to, or death of, personnel or long term health hazards. CAUTION This highlights an essential operating or maintenance procedure, practice, condition, statement, etc., which if not strictly observed, could result in damage to, or destruction of, equipment or loss of mission effectiveness. WARNINGS and CAUTIONS are used in this manual to highlight operating or maintenance procedures, practices, conditions, or statements considered essential to protection of personnel (WARNING) or equipment (CAUTION). WARNINGS and CAUTIONS immediately precede the step or procedure to which they apply. WARNINGS and CAUTIONS consist of four parts: a heading (WARNING, CAUTION, or Icon); a statement of the hazard, minimum precautions, and possible result if disregarded. NOTEs may precede or follow the step or procedure, depending upon the information to be highlighted. The heading used and the definitions are as follows. NOTE This highlights an essential operating or maintenance procedure, condition, or statement. 4. HAZARDOUS MATERIALS WARNINGS. Consult the Material Safety Data Sheets (MSDS) (Occupational Safety and Health Administration (OSHA) Form 20 or equivalent) for specific information on hazards, effects, and protective equipment requirements. If you do not have a MSDS for the material involved, contact your supervisor, or the base Safety or Bioenvironmental Engineering Offices. 5. SAFETY PRECAUTIONS. The following safety precautions SHALL be observed while performing procedures in this manual. CAUTION AROUND LIVE CIRCUITS. Operating personnel must observe safety regulations at all times. Do not replace components or make adjustments inside equipment with the electrical supply turned on. Under certain conditions, such as residual charges on capacitors, danger may exist even when the power control is in the off position. To avoid injuries, always disconnect power, discharge and ground circuit before touching it. Adhere to all lockout/tag-out requirements. ix T.O. 33B-1-2 DO NOT SERVICE ALONE. Under no circumstances should any persons perform maintenance on the equipment except in the presence of someone who is capable of rendering aid. RESUSCITATION. Personnel working with or near high voltage SHALL be familiar with modern methods of resuscitation. Such information may be obtained from the Director of Base Medical Services. FINGER RINGS AND OTHER JEWELRY. Remove rings, watches, and other metallic objects during all maintenance activity that may cause shock, burn, or other hazards. Snagged finger rings have caused many serious injuries. PERSONAL PROTECTIVE EQUIPMENT (PPE). The work center supervisor SHALL contact the Base Bioenviron- mental Office and/or the Base Safety Office for a list of approved protective clothing/equipment (gloves, apron, eye protection, etc.) for the chemicals, materials, and tools being used. Use nitrile, neoprene, or other protective gloves, aprons, and goggles. The Base Bioenvironmental Office SHALL approve these items in writing. PPE SHALL be worn when and where directed to do so by the Base Bioenvironmental Office. COMPRESSED AIR. Use of compressed air can create an environment of propelled foreign particles. Excessive air pressures MAY cause injury. NDI Labs typically use compressed air reduced to less than 30-psig and used with effective chip guarding and personal protective equipment (PPE). Lab supervisors SHALL contact the local Wing Safety Office for guidance. PRECAUTIONS WITH EYEWEAR. Personnel who wear contact lenses shall identify this to their supervisor, refer to the appropriate material safety data sheets (MSDS) for possible hazards involved in wearing contact lenses around chemicals, and abide by the guidance for that chemical. Photochromatic lenses (lenses that darken when exposed to sunlight or ultraviolet light), sunglasses, and colored contacts reduce the visibility of fluorescent indications. This leads to the possibility of faint indications not being seen by the inspector. Therefore, glasses with photochromatic lenses, sunglasses or colored contact lenses SHALL NOT be worn when performing fluorescent penetrant or fluorescent magnetic particle inspections. SAFETY WITH BLACK LIGHTS. Black light bulbs SHALL NOT be operated without proper filters. Cracked, chipped, or ill-fitting filters SHALL be replaced before using the lamp. Unfiltered ultraviolet radiation can be harmful to the eyes and skin. Prolonged direct exposure of hands to the filtered black light main beam may be harmful. Suitable gloves SHALL be worn when exposing hands to the main beam; UV-A filtering safety glasses, goggles, or face shields SHALL also be worn. A black light bulb heats the external surfaces of the lamp housing. The temperature of some operating black light bulbs reaches 750°F (399°C) or more during operation. The temperature is not high enough to be visually apparent, but it is high enough to cause severe burns with even momentary contact of exposed body surfaces. Extreme care SHALL be exercised to prevent contacting the housing with any part of the body. These temperatures are also above the ignition or flash point of fuel vapors. These vapors WILL burst into flames if they contact the bulb. These black lights SHALL NOT be operated when flammable vapors are present. SOLVENTS, CHEMICALS, AND OTHER TOXIC MATERIALS. Solvents used may contain aromatic, aliphatic, or halogenated compounds. Many are flammable while others may decompose at elevated temperatures. Solvents SHALL be kept away from heat and open flames. Vapors also may be harmful to personnel, thus adequate ventilation SHALL be used. Contact with skin and eyes SHALL be avoided. Solvents SHALL NOT be ingested. Waste material disposal SHALL be according to applicable directives or as specified by the local Bioenvironmental Engineer/Environmental Management Offices. Keep cleaners/chemicals in approved safety containers and maintain minimum quantities. Some cleaners/chemicals may have an adverse effect on skin, eyes, and respiratory tract. Observe manufacturer’s WARNING labels; Material Safety Data Sheet (MSDS) instructions for proper handling, storage, and disposal; and current safety directives. Use cleaners/ chemicals only in authorized areas. Discard soiled cloths into approved safety cans. Consult the local Bioenvironmental Engineer for specific protective equipment and ventilation requirements. USE OF RESPIRATORS. Dry developer particles are not toxic materials. However, like any solid foreign matter, they SHALL NOT be inhaled. Air cleaners, facemasks, or respirators may be required. The Base Bioenvironmental Engineer SHALL be consulted if the process generates airborne particles. EXPOSURE TO SF6 GAS. Exposure to excessive amounts of Sulphur Hexafluoride (SF6) gas can cause asphyxiation by displacing oxygen in the air. Care SHALL be taken not to release large quantities of SF6 gas into unvented work areas. The amount leaked into the air while performing normal X-ray tube repair does not create an asphyxiation hazard. When SF6 is heated, it liberates hazardous fluorine gas into the air. This possibility of producing fluorine gas exists in most X-ray tube heads. Precautions SHALL be taken to guard against the inhalation of the gas released from X-ray tubes that have been energized. x  T.O. 33B-1-2 IMPROPER CLEANING PROCEDURES. Improper cleaning procedures/materials can cause severe damage to the material under inspection. Preparation of parts to include but not limited to paint removal and chemical etching SHALL be accomplished by maintenance personnel who are properly trained, highly skilled, and experienced in those particular specialties and are aware of the effects on the part/material due to the use of these chemicals and methods. T.O. 1-1-691 applies to the Air Force, T.M. 1-1500-344-23 applies for the Army; and N.A. 01-1A-509 applies for the Navy and Marine Corps. PRECAUTIONS DURING RADIOGRAPHIC INSPECTIONS. Exposure to excessive X or gamma radiation is harmful to personnel and especially an unborn fetus. All applicable safety precautions SHALL be complied with. While most X-ray equipment is designed to minimize the danger of exposure to direct or stray radiation, certain precautions SHALL be observed. Failure to comply with safety procedures may result in serious injury to personnel. Coordinate all operational changes with the Base Radiation Safety Officer. Radiation protection requirements are discussed further in (see T.O. 33B-1- 1) for additional safety information. (NAVY ONLY: Radiation safety guidance is provided by NAVSEA S040-AARAD- 010.) PRECAUTIONS DURING PENETRANT INSPECTIONS. Penetrant inspection includes the use of black light and exposure to flammable chemicals that may affect skin, eyes, and respiratory tract. Care SHALL be exercised when using hot black lights so as not to burn hands, arms, face, or other exposed body areas. Wear nitrile, neoprene, or other approved gloves and keep the insides of gloves clean when handling penetrant materials. When processing parts through chemicals in the stationary lines, chemical goggles, rubber apron, and protective gloves SHALL be worn. During times of portable inspection, a minimum of protective gloves and eye protection SHALL be worn. Consult your local Bioenvironmental and Safety offices for further guidance. Ensure the Base Bioenvironmental Office performs an adequate surface area exhaust ventilation evaluation annually. When recommended by the Base Bioenvironmental Engineer, an approved respirator SHALL be worn when working in areas where adequate ventilation cannot be practically provided. The use of visible dye penetrant is PROHIBITED on engine, aircraft, and missile parts except for those with specific engineering approval for each inspection. Magnetic particle inspection includes exposure to chemicals, ultraviolet light, and electrical current. Rubber insulating floor matting, rated for the voltage of the equipment being worked on, SHALL be used in front of magnetic particle units. Care SHALL be exercised when using hot black lights so as not to burn hands, arms, face, or other exposed body areas. Wear nitrile, neoprene, or other approved gloves and keep the insides of gloves clean when handling magnetic particle materials. When processing parts through chemicals in the stationary lines, chemical goggles, rubber apron, and protective gloves SHALL be worn. During times of portable inspection, a minimum of protective gloves and eye protection SHALL be worn. Consult your local Bioenvironmental and Safety offices for further guidance. Ensure the Base Bioenvironmental Office performs an adequate surface area exhaust ventilation evaluation annually. 6. ACCESS TO SURFACES AND PART PREPARATION. Access to aircraft surfaces (e.g. panel removal) requiring Nondestructive Inspection, SHALL be accomplished by maintenance personnel who have properly documented training and are highly experienced in those particular specialties. Improper cleaning procedures/materials can cause severe damage to the material under inspection. Preparation of parts to include, but not limited to, paint removal and chemical etching SHALL be accomplished by maintenance personnel who are properly trained, highly skilled, and experienced in those particular specialties and are aware of the effects on the part/material due to the use of these chemicals and methods. T.O. 1-1-691 applies for the Air Force, T.M. 1-1500-344-23 applies for the Army, and N.A. 01-1A-509 applies for the Navy and Marine Corps. xi/(xii Blank)  T.O. 33B-1-2 CHAPTER 1 NONDESTRUCTIVE INSPECTION METHODS, GENERAL INFORMATION SECTION I INTRODUCTION 1.1 INTRODUCTION. 1.1.1 Purpose. Nondestructive Inspection (NDI) is the inspection of a structure or component in any manner that will not impair its future usefulness. The purpose of the inspection may be to detect flaws, measure geometric characteristics, determine material structure or composition, or it may characterize physical, electrical, or thermal properties without causing any changes in the part. The five standard NDI disciplines include: Liquid Penetrant Magnetic Particle Eddy Current Ultrasonic Radiography 1.1.2 Scope. This publication contains general procedures and process controls for NDI methods and SHALL be used only when specific inspection instructions are not available and as test part geometry, material, coating, and surface finish permits. It is intended that these general procedures be used as directed and with guidance from an NDI Level 3 or the engineering authority for the weapon system or commodity item being tested. The procedures in this manual can be used as a stand-alone inspection instruction when T.O. 33B-1-2, T.O. 33B-1-1 or a MIL Standard is referenced as the inspection document, or when no specific inspection criteria exist. The general procedures are written for use by an experience level 2 or equivalent (5-level) technician. In some instances, an experienced task certified level 1 or equivalent (3-level) technician can effectively use the general procedures. It is recommended that an experienced level 2 or higher technician thoroughly review the procedures with the task certified level 1 technician prior to approving use in an actual inspection. The process control procedures are written so that a level 1 or equivalent (3-level) technician can perform the checks with limited training and supervision. Guidance for development of NDI procedures is contained in MIL-DTL-87929C, Appendix F. NDI procedures contained in this manual are detailed step-by-step instructions with illustrations so a qualified NDI technician can perform the required inspection. In addition, this manual provides some general safety guidance for NDI inspectors. Other safety guidelines may apply and SHALL be used as required. 1.1.3 Format of Procedures. Though MIL-DTL-87929C is a directive for NDI Work Packages, it provides the proper format for detailed/repetitive NDI procedures. To ensure continuity of inspections, all on and off equipment maintenance NDI manuals (e.g. -9, -36, etc.) SHALL be written to adopt the special requirements of MIL-DTL-87929C into MIL-PRF- 83495 when writing NDI procedures for these maintenance manuals. An individual qualified and certified to Level 3 in accordance with NAS 410 in the inspection method being used, SHALL approve all written procedures. 1.1.4 Knowledge of NDI. NDI methods in the hands of a trained and experienced technician are capable of detecting flaws or defects with a high degree of accuracy and reliability. It is important maintenance-engineering personnel are fully knowledgeable of the capabilities of each method but it is equally important they recognize the limitations of the methods. Rarely should an NDI method ever be considered conclusive. Often but not always, a defect indication detected by one method must be confirmed by another method to be considered reliable. The equipment is highly sensitive so the limits for acceptance and rejection are as much a part of an inspection as the method itself. As an example, ultrasonic inspection criteria must be designed to overlook these ‘‘normal’’ indications and to discriminate in favor of the discontinuities that will affect the service of the component. 1.1.5 NDI Points-of-Contact. To fully utilize the content of this Technical Order it may become necessary to contact members of the Air Force NDI engineering community for technical guidance. The following points-of-contact are current at the time of publishing. Chief, Air Force NDI Program Office, AFRL/MLS-OL. DSN: 339-4322, Comm: 405-739-4322. ALC NDI Program Manager. Oklahoma City Air Logistics Center. DSN: 336-5008, Comm: 405-736-5008. ALC NDI Program Manager. Ogden Air Logistics Center. DSN: 586-4496, Comm: 801-586-4496. 1-1 T.O. 33B-1-2 ALC NDI Program Manager. Warner Robbins Air Logistics Center. DSN: 468-4489, Comm: 912-926-4489. NDI Field Program Manager. Air Force NDI Program Office, AFRL/MLS-OL. DSN: 339-3768, Comm: 405-739- 3768. Technical Content Manager 33B series Technical Orders. Air Force NDI Program Office, AFRL/MLS-OL. DSN: 884- 1880, Comm: 405-734-1880. 1-2  T.O. 33B-1-2 SECTION II PROCESS CONTROLS 1.2 PROCESS CONTROLS. NOTE Specific process controls are discussed in section two of Chapter 2 through Chapter 6 of this manual. 1.2.1 Reason for Controlling the Process. Process control is an essential ingredient in achieving consistent and reliable results with NDI inspections. A well regimented NDI process control program will not allow conditions to develop that render inspection methods as a source of misinformation. This misinformation may take two forms: 1) When NDI determines a part is defective, when in truth it is not, resulting in a false call. This is a waste of resources and an unnecessary reduction in mission capability. 2) Even more dangerous is determining a part to be serviceable when in fact it is defective resulting in a missed call. Both forms of misinformation can be minimized through the implementation of effective process control. 1.2.2 Scope of Process Control. All aspects of these categories are interrelated. They have to be tuned to each other to achieve valid inspection results. If any one of these requirements is altered, the final outcome of the inspection will change, regardless of the inspector’s proficiency. 1.2.2.1 Process control is a general term used to encompass the actions and documentation required by established directives and logic. These controls are necessary for an NDI method to be effective in detecting conditions of interest (e.g., cracks, foreign objects, corrosion, alignment of parts, and thickness of parts). 1.2.2.2 Areas that fall within the scope of process control are as follows: Training and the demonstrated practical skills of inspectors. Inspection environment. (e.g., temperature, specific type and levels of light, safety, and human engineering.) Material control. (e.g., serviceability of ultrasonic transducers, eddy current probes, penetrant materials, X-ray film and chemicals, and magnetic particle suspensions.) Equipment control. (e.g., operational and performance capability or Test Measurement Diagnostic Equipment (TMDE)/user calibration.) Written inspection instructions. (e.g., adequate, -9, -26, and -36 technical orders and Time Compliance Technical Orders (TCTOs).) Adherence to written inspection instructions. (e.g., distinguishing requirements dictated by specific NDI procedures versus commonly accepted basic NDI practices.) Table 1-1. Frequency for Process Control Liquid Penetrant Interval Para System Performance Test (Cracked Chrome Panels) Weekly 2.2 System Performance Test (Starburst-PSM) (Depot Daily 2.3 Only) Water Wash Pressure Daily or Prior to use 2.12 Water Wash Temperature Daily or Prior to use 2.12 Black Light Intensity Daily or Prior to use 3.2.6 Inspection Booth Cleanliness Daily 2.4 Penetrant Contamination Daily or Prior to use 2.9.2 Developer Contamination (Aqueous: Soluble and Sus- Daily or Prior to use 2.10.2 pendable) 2.10.4 2.10.5 Developer Coverage (Aqueous: Soluble and Suspend- Monthly 2.10.1 able) 1-3 T.O. 33B-1-2 Table 1-1. Frequency for Process Control - Continued Liquid Penetrant Interval Para Dry Developer Condition Daily or Prior to use T.O. 33B-1-1 2.6.8.7.1 2.6.10.4.9.2 Penetrant (Method A) Water Contamination Monthly 2.7 Lipophilic Emulsifier Performance Test Monthly 2.8 Hydrophilic Remover Concentration Monthly 2.9 Hydrophilic Remover Performance Test Monthly 2.9.3 Developer Concentration (Aqueous: Soluble and Sus- Monthly 2.10 pendable) 2.10.3 Ambient White Light 60 Days 3.2.6.1 Drying Oven Calibration IAW T.O. 33K-1-100-CD-1 T.O. 33B-1-1 Magnetic Particle Testing Interval Para Concentration/Suspension Settling Test Prior to use and after 8- hours of contin- 3.2.8 uous use Vehicle Fluorescence Test In Conjunction with Concentra- 3.2.9 tion/Suspension Settling Test System Effectiveness Test and In-use Field Indicator Weekly 3.2 Check 3.2.12 Ambient Light Check 60 Days 3.2.6.1 Black Light Intensity Daily or Prior to use 3.2.6 Amperage Indicator Check 90 Days 3.2.3 Quick Break 90 Days 3.2.4 Water Break Test (Water Baths Only) Daily or Prior to use 3.2.11 Dead Weight 90 Days 3.2.5 Eddy Current Interval Para Probe/Slot Test 180 days 4.2 Ultrasonic Inspection Interval Para Vertical Linearity Quarterly 5.1.1 Horizontal Linearity Quarterly 5.1.2 Sensitivity Check Quarterly 5.1.3 Resolution Check Quarterly 5.1.4 Dead Zone Check Quarterly 5.1.4.2 Angle Beam Point of Incident Quarterly 5.1.7 Angle Beam Angle Determination Quarterly 5.1.9 Angle Beam Skew Angle Quarterly 5.1.8 Radiography Inspection Interval Para Safelight Fog Evaluation Initial install and requirements described 6.1 in indicated paragraphs Interlock Functional Check Prior to X-ray operation 6.1.6 Interlock System Inspection 180 Days 6.1.6 Safe Light Filter Check Monthly 6.1.5 Fixer Control Monthly 6.1.4 Development Process Weekly 6.1.3 1-4  T.O. 33B-1-2 CHAPTER 2 FLUORESCENT LIQUID PENETRANT INSPECTION SECTION I FLUORESCENT LIQUID PENETRANT INSPECTION GENERAL PROCEDURE 2.1 FLUORESCENT LIQUID PENETRANT INSPECTION GENERAL PROCEDURE. Fluorescent penetrant inspection is an effective method for detecting surface breaking discontinuities in metallic parts. It can provide excellent detection sensitivity; however, the effectiveness of the method is highly dependent on strict control of the process. Penetrant material SHALL be listed on QPL SAE AMS 2644 and process control requirements must be followed. Black lights SHALL be capable of producing ultraviolet light intensity of at least 1000 micro-watt per square centimeter and SHALL NOT emit more than 2 ft-candles of white light. Ultraviolet and white-light measurements SHALL be measured 15 inches from the lens. Ambient light conditions SHALL be as low as possible when performing inspections under black light illumination. The ambient light SHALL NOT exceed 2 ft-candles in an inspection booth. Test part surfaces SHALL be free of coatings and contaminants. Inspectors SHALL meet the training and certification requirements stated in paragraph 1.2 of T.O. 33B-1-1. Table 2-1. Fluorescent Penetrant Advantages and Limitations Advantages Disadvantages/Limitations ♦ Capable of complete coverage of complex ♦ Flaw opening must be open at the surface of test part shapes ♦ Capable of detecting small surface discontinu- ♦ Surface condition must be relatively smooth and free of ities coatings and contaminants ♦ Is effective on ferrous and nonferrous metals ♦ Effectiveness is highly dependent on process control and and a variety of other materials cleanliness of inspection surface ♦ Inexpensive and requires less training than ♦ Surface coating removal procedures affect process sensi- other methods tivity (when possible coating removal SHOULD be lim- ited to chemical stripping processes) ♦ Readily adaptable to large volume processing ♦ Cannot perform inspections with part temperature below 40°F or above 125°F 2.1.1 Preparation of Part. WARNING Due to the oily nature of most penetrants, they SHALL NOT be used on parts, such as assemblies, where they cannot be completely removed and will subsequently be exposed to gaseous or liquid oxygen. Oils, even residual quantities, may explode or burn very rapidly in the presence of oxygen. Only materials specifically approved for this application SHALL be used if penetrant inspection is required and complete removal of the residue is not possible. The applicable Weapons System Technical Order and/or the responsible ALC NDI Manager SHALL direct use of these materials. 2-1 T.O. 33B-1-2 Some penetrant materials may contain sulfur and/or halogen compounds (chlorides, fluorides, bromides, and iodides). These compounds may cause embrittlement or cracking of austenitic stainless steels if not completely removed prior to heat-treating or other high temperature exposure. Entrapped halogen compounds may also cause corrosion of titanium alloys if not completely removed after the inspection is completed and the part is subjected to elevated temperatures. The applicable Weapons System Technical Order and/or the responsible ALC NDI Manager SHALL direct use of these materials. All relevant safety equipment and procedures directed by Chapter 2 Section VIII of TO 33B-1-1 and AFOSH Standard 91-501 are required in this inspection procedure and SHALL be adhered to. Correct part preparation is vital to consistent and effective penetrant inspection results. Coating removal SHALL be accomplished IAW applicable Technical Order procedures and performed by trained and certified personnel. CAUTION Chlorinated hydrocarbon solvents such as trichloroethylene, trichloroethane, carbon tetrachloride, and Freon (including its use in aerosol spray cans) SHALL NOT be used on titanium. Penetrant equipment contacting titanium such as parts-holding baskets SHALL NOT be coated with cadmium, lead, silver, or zinc. Failure to comply with these cautions could have a detrimental effect to the structural capabilities of the components being prepared. NOTE When accomplishing penetrant inspections, the preferred finish removal method is chemical. If the finish must be removed by mechanical means, it is recommended an acid etch (0.0004 inch minimum removal) be performed prior to penetrant inspection. Trained and qualified personnel SHALL perform acid etching IAW the applicable - 3 series Technical Orders. Some organizations may require acid etching; consult the applicable Weapons System Technical Order and/or the responsible Weapons System SPO. a. Have all surface coatings removed from the area to be inspected as required. Anodized coatings SHALL NOT be stripped from aluminum alloys. Refer to the applicable -23 series Technical Orders and the Structural Maintenance or Corrosion Control Shop for coating removal procedures. b. Perform a final wipe down of the part with a clean lint free cloth or paper towel dampened with an approved cleaner. 2.1.2 Penetrant Application Procedure. Penetrant methods C and D are the most common processes used at Air Force NDI laboratories and are covered in this procedure. Methods A and B penetrant procedures SHALL NOT be used unless specific approval and instruction is provided by the Weapon System SPO or the ALC NDI Manager. Minimum penetrant sensitivity levels are shown in Table 2-2. Most NDI Laboratories will use level 3 (High) sensitivity penetrant materials in their stationary penetrant process. Level 3 penetrant is generally adequate for most applications unless otherwise specified by technical order or engineering directive. If background fluorescence is noticeably high, a decrease in sensitivity level may be required. Titanium and some rotating engine parts require and ultra high-level penetrant sensitivity, small amounts of various penetrants may need to be purchased to meet the requirements of all test part materials. Various sensitivity level penetrants can easily be purchased in small quantities from any reliable NDI product distributor. Contact the appropriate ALC NDI Manager for assistance. Table 2-2. Material and Minimum Penetrant Sensitivity Level Materials Penetrant Sensitivity Level Nonaircraft Rough Cast or Weld 2 (Medium or Normal) Magnesium and Aluminum 3 (High) Steels and Nickel Alloys 3 (High) Titanium and some rotating engine parts 4 (Ultra High) 2-2  T.O. 33B-1-2 a. Apply the penetrant to the inspection area by brushing, swabbing or spraying (method C) or brushing, swabbing, dipping, flowing or spraying (method D). Reapply penetrant as necessary to prevent the penetrant from drying during the dwell. b. Allow penetrant to dwell for the minimum time defined in (see Table 2-3). The drain dwell mode is the preferred method of penetrant dwell; the immersion dwell mode is used as directed by a specific inspection instruction. Table 2-3. Penetrant Dwell Times Temperature 40 – 60°F Minimum Service Induced Fatigue Cracks 60 minutes Stress Corrosion Cracks 240 minutes Temperature 60 – 125°F Minimum Service Induced Fatigue Cracks 30 Minutes Stress Corrosion Cracks 240 Minutes 2.1.3 Penetrant Removal Procedure. During the penetrant removal process, it is important to remove all the surface penetrant without removing penetrant contained in defects. 2.1.3.1 Method C (Solvent Wipe) Penetrant Removal. CAUTION The solvent-remover SHALL NOT be applied directly onto the inspection surface to remove excess penetrant. a. Following the penetrant dwell period, the surface is wiped with a clean, dry lint-free cloth or towel to remove the major portion of surface penetrant. The proper procedure is to make a single pass and then fold the cloth or towel over to provide a clean cloth surface for each wipe. b. When the surface penetrant has been reduced to a minimum, remove any remaining residual penetrant using a clean lint-free cloth or towel lightly moistened with an approved solvent remover. The amount of solvent applied to the cloth is critical. The cloth is only lightly moistened with the application of a fine spray of solvent. The cloth SHALL NOT be saturated by pouring, immersion, or excessive spraying. c. A black light is used to examine the part surface during the intermediate and final wiping stages. The surface of the rag should also be examined under black light during the final solvent wipe. If the rag shows more than a trace of penetrant, it is folded to expose a clean surface, remoistened with solvent, and again wiped across the part. This step is repeated until the fluorescent background on the part is minimal and the rag shows little or no trace of penetrant. d. After the solvent wipe, conduct a final wipe down with a clean dry cloth or towel to remove any residual solvent remaining on the part surface. 2.1.3.2 Method D (Hydrophilic Remover) Penetrant Removal - Immersion. CAUTION The correct concentration of hydrophilic remover is critical to the Method D process. Consult the manufacturer’s guidelines for remover concentration criteria. Penetrant removal for Method D immersion begins with a clean water rinse. Depending on the complexity of the test part, the rinse should be between 30 and 120-seconds. Maintain a rinse angle of 45 to 70°, water temperature between 50 and 100°F, and water pressure below 40 psi. 2-3 T.O. 33B-1-2 a. Following the pre-rinse, an immersion dwell in hydrophilic remover is used to remove the remaining surface penetrant. The remover is slightly agitated to allow fresh remover to be exposed to the part, this is usually accomplished with low-pressure shop air at the bottom of the remover tank. Agitation can also be accomplished by gently stirring the test part in the remover. Dwell times will vary between 30 and 120-seconds. If a predetermined dwell time is not available for the in-use remover, start with a 30-second immersion dwell and then perform the rinse. If the background is unacceptable perform another 15-second immersion dwell then rinse and repeat the procedure until the part has acceptably low background fluorescence. Total remover immersion SHALL NOT exceed 120- seconds. b. After the immersion dwell, rinse the remover and remaining surface penetrant from the part. Perform the rinse under black light to the same criteria as the pre-rinse. Stop the rinse when background fluorescence is at a minimum. It is important to keep the immersion dwell and the water rinse to the lowest time possible and still obtain low background fluorescence. 2.1.3.3 Method D (Hydrophilic Remover) Penetrant Removal – Spray. CAUTION The hydrophilic remover concentration SHALL NOT exceed 5-percent when using spray application Penetrant removal for Method D spray begins with a clean water rinse. Depending on the complexity of the test part, the rinse should be between 30 and 120-seconds. Maintain a rinse angle of 45 to 70°, water temperature between 50 and 100°F, and water pressure below 40 psi. a. Following the pre-rinse, use a garden sprayer to spray a 5-percent concentration of hydrophilic remover onto the inspection surface. Perform remover application under black light illumination to ensure optimum penetrant removal. Care must be taken not to over-remove the surface penetrant. Maximum remover spray time SHALL NOT exceed 120 seconds. Use only the minimum spray time required to obtain low background fluorescence. b. A final water-only spray is used to remove the hydrophilic remover from the surface. Depending on the complexity of the test part, the rinse should be between 30 and 120-seconds. Maintain a rinse angle of 45 to 70°, water temperature between 50 and 100°F, and water pressure below 40 psi. 2.1.4 Developer Application and Drying Procedure. Developers are used to draw penetrant from discontinuities and spread it out over adjacent part surfaces increasing the visibility of the indication. Developers also provide a contrasting background for the penetrant material. 2.1.4.1 Dry Developer (Form a) Application. WARNING Dry developer particles are not toxic materials; however, inhalation should be avoided. Air cleaners, facemasks, or respirators may be required. The Base Bioenvironmental Engineer SHALL be consulted if the process generates airborne particles. NOTE Dry developers SHALL NOT be used unless specifically approved by the applicable Weapons System Technical Order and/or the responsible ALC NDI Manager. Dry developers SHALL NOT be applied to a part until the surface is thoroughly free of moisture. The presence of even a little moisture will interfere with the developer action and small flaws may be missed. a. Dry the test part completely before applying dry developer. 2-4  T.O. 33B-1-2 b. Dry developer is applied by blowing with a bulb type blower, immersing in a container, pouring the powder over the part, use of a dust or fog chamber, or an electrostatic system. c. Shake or carefully blow off (with bulb type blower) the excess developer, if using compressed air it SHALL be below 5-psig. For small areas, a bulb type blower is recommended. d. Allow developer to dwell using the dwell times in (Table 2-4). 2.1.4.2 Water-soluble (Form b) Developer Application:. Water-soluble developer is the most commonly used devel- oper at Air Force NDI laboratories. It is the recommended developer for method D penetrants because it provides a better background than dry or water suspended developers and does not require agitation. a. Apply water-soluble developer by dipping or flowing. Allow the part to drain and rotate to prevent developer pooling. b. Place the test part into a clean dryer oven with a temperature of 140°F or less. (Depots with automatic or semi- automatic systems SHOULD refer to the process order for the system or test part to set drying oven temperature.) Rotate the part as required to prevent developer pooling. c. Remove the test part from the drying oven as soon as the part is completely dry. d. Allow the developer to dwell. Dwell time begins when the test part is completely dry. (Refer to Table 2-4 for developer dwell times.) 2.1.4.3 Water-Suspended (Form c) Developer Application:. Water-suspended developers are applied in the same manner as water-soluble with one exception; suspended developers require thorough agitation prior to application to the test part. Refer to paragraph 2.1.4.2 for procedures. 2.1.4.4 Nonaqueous (Form d) Developer Application:. Nonaqueous solvent-suspended developers are generally packaged in aerosol spray cans. It is most often used in portable inspections but is also used in the bleed-back procedures for methods C and D. It provides an excellent background and is the most sensitive developer form. NOTE Nonaqueous developers SHALL NOT be applied to a part until the surface is thoroughly free of moisture. The presence of even a little moisture will interfere with the developer action and small flaws may be missed. a. Ensure the test part is completely dry before applying nonaqueous developer. b. Shake spray can thoroughly before use. c. Spray a light even coat of developer over the inspection area. d. Allow the developer to dwell. (Refer to Table 2-4 for developer dwell times.) e. Inspect the test part after sufficient dwell. NOTE Test parts SHOULD NOT be exposed to high intensity black light during the developer dwell. Long exposure to black light will cause penetrant indications to fade. Table 2-4. Developer Dwell Times Temperature 40 – 60°F Nonaqueous Developer (Spray Cans) Minimum Maximum Service Induced Fatigue Cracks 20 minutes 60 minutes Stress-Corrosion Cracks 60 minutes 120 minutes 2-5 T.O. 33B-1-2 Table 2-4. Developer Dwell Times - Continued Temperature 40 – 60°F Nonaqueous Developer (Spray Cans) Minimum Maximum Aqueous Developer (Water Soluble and Suspendable) Minimum Maximum Service Induced Fatigue Cracks 30 minutes 120 minutes Stress-Corrosion Cracks 60 minutes 120 minutes Dry Developer Minimum Maximum Service Induced Fatigue Cracks 30 minutes 240 minutes Stress-Corrosion Cracks 60 minutes 240 minutes Temperature 60 – 125°F Nonaqueous Developer (Spray Cans) Minimum Maximum Service Induced Fatigue Cracks 10 minutes 30 minutes Stress-Corrosion Cracks 30 minutes 60 minutes Aqueous Developer (Water Soluble and Suspendable) Minimum Maximum Service Induced Fatigue Cracks 15 minutes 60 minutes Stress-Corrosion Cracks 30 minutes 120 minutes Dry Developer Minimum Maximum Service Induced Fatigue Cracks 15 minutes 120 minutes Stress-Corrosion Cracks 30 minutes 240 minutes 2.1.5 Fluorescent Penetrant Interpretation. Fluorescent penetrant interpretation is done under blacklight illumination in an inspection booth or darkened area. Portable inspections may require a locally manufactured or purchased tent-like apparatus made of dark cloth or canvas to reduce ambient light levels and enhance inspection sensitivity. Identify indications as linear or rounded and measure the largest dimension of the indication for comparison to acceptance criteria. A rounded indication has length that is less than 3 times its width. A linear indication has a length 3 or more times its width. Evaluate indications according to limits in technical data. If technical data is not specific or no technical data is available, consider all linear indications relevant and rounded indications 1/16th of an inch or larger relevant for both aircraft and nonaircraft test parts. 2.1.5.1 Defects will generally be linear or aligned rounded or pinpoint indications resulting from: Fatigue cracks. Stress corrosion cracks. Intergranular corrosion. 2.1.5.2 Non-relevant indications will not be marked. These indications can be identified by using the bleed-back method (see paragraph 2.1.6). Non-relevant indications are generally: Scratches. Nicks. Tool marks. Machined marks. 2.1.5.3 Defects should be marked on the part surface with an approved marking pencil. Measure the defect and note identifying characteristics. Describe the defect in detail including its size (length), location, and orientation. Document inspection findings IAW Air Force Instructions and local directives. An example of a good defect description is as follows: ‘‘Method C penetrant inspection of welds on transfer case part number 128-6380. Crack noted and marked on the inlet to case weld. The indication is sharp, well defined, bright, and linear. The defect is 2.125 inches long and runs down the center of the weld crown.’’ 2-6  T.O. 33B-1-2 NOTE Air Force NDI personnel SHALL NOT make serviceability determinations except as described in AFI 21-101 (field units only). The role of the NDI inspector is normally limited to providing a detailed description of the defect and its location. Disposition and repair responsibility for a flawed part or airframe lies with Structural Maintenance personnel or the owning workcenter and the appropriate engineering authority. 2.1.6 Bleed-Back Method. The bleed-back method is used to evaluate discontinuities for relevance. Non-relevant indications such as scratches, nicks, and tool marks will generally not hold enough penetrant to redevelop indications after the initial indications have been removed. The following is a typical bleed-back procedure: a. Use a clean dry cloth or paper towel to wipe the indication area. b. Lightly dampen the corner of a clean cloth or cotton swab with an approved solvent remover. Carefully wipe the indication area once with the solvent dampened cloth or cotton swab. After the solvent has evaporated, examine the bare surface under black light illumination for evidence of the indication as it begins and continues to develop without developer applied. Use of a 5-10X magnifier is recommended. If redevelopment of the indication occurs, it is be considered a relevant indication. c. If no indication is observed apply a light coat of nonaqueous (form d) developer. d. Again, after the developer solvent has evaporated, carefully examine the surface under black light illumination for evidence of the indication as it begins and continues to develop with developer applied. Use of a 5-10X magnifier is recommended. Allow a minimum redevelop time as defined in Table 2-4. If redevelopment of the indication occurs, it is considered a relevant indication. Non-relevant indication should not demonstrate any redevelopment. 2.1.7 Post Cleaning. Penetrant and developer residues SHALL be completely removed prior to reapplication of the surface finish. Dry developers, as well as water soluble and suspendable developers, are removed easily with a warm water rinse. Penetrants used in these processes are removed with warm water and an approved mild detergent. A soft bristled bush is effective for recessed areas, and around fasteners and other obstacles. When performing portable inspection, penetrant and developer residues are removed by first wiping with a clean dry cloth or paper towel then wiping again with a cloth or paper towel dampened with an approved solvent. 2-7 T.O. 33B-1-2 SECTION II FLUORESCENT LIQUID PENETRANT INSPECTION PROCESS CONTROL 2.2 SYSTEM PERFORMANCE TEST PROCEDURE - CRACKED-CHROME PANELS. CAUTION Use care in handling and storing the panels. Do not drop, hit, or place mechanical stress on the test panels. Do not attempt to bend or straighten the test panels. Do not expose the test panels to temperatures above 212°F (100°C). Thorough ultrasonic cleaning of cracked-chrome panels after each use is mandatory. The panels are easily damaged by rough handling or when dropped. Damaged or degraded panels SHALL be immediately replaced. The cracked-chrome panels are used to evaluate the liquid penetrant system’s performance. They provide a side-by-side comparison of in-use liquid penetrant materials with a reference standard of the same material that was set aside prior to the material being put into service. The cracked-chrome panels readily show small or gradual changes in penetrant material sensitivity. Tests made with cracked-chrome panels do not provide useful information on background fluorescence caused by surface roughness or the ability of a liquid penetrant to reveal small cracks in the presence of severe background fluorescence caused by surface roughness or porosity. 2.2.1 Equipment and Materials Required for Cracked-Chrome Panel Test. Equipment and materials needed to perform the cracked-chrome panel test are listed below: In-use penetrant, remover, and developer. Reference penetrant, remover, and developer. Small glass or paper containers. 2 each acid brushes or swabs. 2 each cracked chrome panels. (Cracked-chrome panels are delivered from the manufacturer in sets of two. These panels SHALL be used together and not substituted with any other panels. When one panel is damaged or degraded the whole set SHALL be replaced.) Hydrophilic fluorescent liquid penetrant line and associated equipment. (The cracked-chrome panel may also be performed with method A, B, and C penetrant material.) (See paragraph 2.2.6 thru paragraph 2.2.8) 2.2.2 Procedure for Cracked-Chrome Panel Test. a. Wipe the cracked-chrome panels with a clean lint free cloth dampened with solvent. Allow to dry and examine under ultra violet light. If residual penetrant is present, clean the panels in accordance with (see paragraph 2.11). b. Pour a small quantity of working bath material and reference material in separate glass or paper containers. To avoid contaminating the entire reference sample, the reference material SHALL NOT be applied to the cracked-chrome panel directly from its storage container. c. Apply penetrant by brushing, swabbing, or flowing. Brushing or swabbing is preferred since it permits better control over the quantity of penetrant applied. Use the working materials on one panel and the reference materials on the other. Use separate brushes or swabs for the working material and the reference. Allow the penetrant to dwell for 5- minutes. d. Perform a pre-rinse of 20-seconds or less. Allow just enough time to remove the surface penetrant. (Coarse spray of plain water at no more than 40 psi with a water temperature between 50 and 100°F) e. Apply remover by immersing the panels in their correlating working bath and reference material. Removal time will be very short, between 10- to 20-seconds. f. Perform a final rinse of 20-seconds or less. (Coarse spray of plain water at no more than 40 psi with a water temperature between 50 and 100°F) g. Apply correlating working bath and reference developer by immersion, flowing, or spraying. (Ensure water- suspended developers are mixed well before applying.) 2-8  T.O. 33B-1-2 h. Place in clean drying oven. Do not allow to sit in the dryer for an extended period, remove as soon as the panels are dry. i. Allow developer to dwell for 5-minutes. The dwell begins after the panels are completely free of moisture. j. Examine the panels side-by-side under black light, first noting the overall brightness and color of the indications. Second, examine each in detail by following individual indications across both panels. Note the presence, absence, or diminishing of crack indications on the working bath panel as compared to the reference sample panel and observe the difference in continuity, size and color. Any distinct difference SHALL be cause for additional testing to determine if the penetrant, remover, or the developer caused the difference in the indications. 2.2.3 Testing for Failed Penetrant. If the system performance test indicates a loss of sensitivity or brightness, use a set of clean, dry cracked-chrome panels to repeat the material test procedure (see paragraph 2.2.2) with the following changes: use the reference samples of remover and developer on both panels. If crack indications on the two panels show clearly visible differences in sensitivity, brightness or color, the penetrant SHALL be replaced. 2.2.4 Testing for Failed Emulsifier/Remover. If there is little or no difference in the crack indications during the penetrant performance test, clean the panels and repeat the performance test procedure to test the emulsifier/remover. Use reference penetrant on both panels and apply the working sample of remover to one specimen and reference remover to the other panel at the appropriate point in the process. Apply reference developer to both panels. If crack indications on the two panels show clearly visible differences in sensitivity, brightness or color, the remover SHALL be replaced. 2.2.5 Testing for Failed Developer. If there is little or no difference in the crack indications during the remover performance test, clean the panels and repeat the performance test procedure to test the developer. Use reference penetrant and remover on both panels and apply the working developer to one panel and the reference developer to the other panel at the appropriate point in the process. If crack indications on the two panels show clearly visible differences in sensitivity, brightness or color, the developer SHALL be replaced. 2.2.6 Lipophilic Penetrant Systems. The removal step is the only difference in performing the cracked-chrome panel test on a lipophilic process. Simply skip step d in the procedure and modify step e so that the panels are immersed in emulsifier and immediately removed. Allow the emulsifier to dwell for 10 to 20 seconds and proceed to step f. 2.2.7 Water Washable Penetrant Systems. For water washable systems the remover and developer steps need to be modified. Skip steps d and e, proceed to step f. Wash the panels as long as necessary to remove all visible penetrant. Do not over wash, the cracks on these panels are shallow and the trapped penetrant can be easily removed by over washing. Since aqueous developer cannot be used with water washable penetrants, a nonaqueous or a dry power developer must be used. Dry the panels in the drying oven and then spray a light even coat of nonaqueous developer on the panels or dip the panels in dry powder developer. Proceed to step i and finish the procedure. 2.2.8 Solvent Removable Penetrant Systems. Solvent removable penetrant systems (spray cans) do not require a 7- day system performance test because the materials are not subject to reuse or degradation. The cracked chrome panel test is required before a new batch of material is put into to service. The material previously used becomes the reference so it is important to test the new material before the old material is completely used up. The remover and developer steps need to be modified; skip steps d, e, and f. The removal step is to wipe the panels with a separate clean dry cloth and then perform another wipe with a separate solvent dampened cloth, repeat the solvent wipe until no penetrant is visible. The developer application step is to spray a light even coat of nonaqueous developer on the panels. Proceed to step i and finish the procedure. 2.3 SYSTEM PERFORMANCE TEST WITH THE PSM STARBURST PANEL (DEPOT ONLY). The system performance test utilizing the PSM panel is a daily check of the entire penetrant system. The panel’s polished half contains five star shaped cracks and is used to monitor changes in penetrant sensitivity, while the grit blasted half is used to test the removal process of the penetrant system. The PSM panel test is ideally suited for high volume workloads because it can be processed directly in the working material along with the first batch of parts at the beginning of the workday. Because the panel is used strictly with in-use penetrant materials, no reference standards are needed. Facilities with automatic or semi-automatic penetrant sys