Equipment Technology and Maintenance Lecture 3

Equipment Technology and Maintenance (Lecture 3)

• Calibration Documentation: Several documents are required for the calibration program. These include a master list of instruments, specifications for each instrument, standard operating procedures for calibrating each instrument type, a calibration plan, internal lab calibration records, calibration certificates from external bodies, and training plans/records for technicians. All records and certificates must be completed, stored, and archived.

Instrument Calibration Index (Calibration Master List)

• The purpose of the master list is to catalog all instruments for a calibration regime and trigger calibrations at predetermined times. Each instrument record should include the last due date, the last calibration date, the expiry date, the next due date, and the calibration period.

Specifications

• Instrument specifications are crucial for calibration and authorization/control. Critical instruments are treated differently from major/reference instruments. Calibration accuracy and range should meet the needs of the measured parameter. The calibration period should balance frequent calibration with possible "as-found" instrument failures. Factors like instrument durability, accuracy requirements, and environmental conditions should be considered.

Calibration Standard Operating Procedure (SOP)

• Calibration SOPs outline the steps necessary for accurately calibrating an instrument. Each SOP should have a unique identification number and be included in the instrument calibration index. The SOP must be signed by appropriate personnel (instrument specialist, process specialist, and quality assurance representative) to indicate acceptance of the calibration instructions, ratings, and accuracy/range. Changes in SOP format must be authorized by the same signatories. Revisions should be kept on a revision-tracking sheet.

Calibration Record

• Records all calibration reports, including the creation date, due date, calibrator, and pass/fail results. The record should include information about the measurement device, calibration SOP number, equipment name, ID number, location, calibration date, calibration due date, calibrator, manufacturer, whether it passed/failed, and remarks.

Calibration Certificates

• Only calibrations meeting accuracy requirements should receive certificates. Calibration certificates should have a unique number and clearly display the instrument's tag number, plant number, or serial number. The certificate should include the calibration date, next due date, expiry date, calibrator's name, and signature.

Calibration Report (Example)

• Calibration reports document each instrument's calibration. The report typically includes equipment details, calibrated by, location, acceptance criteria, calibration reason, standard calibrator information, calibration range, test point reading/standard calibrator, deviations, % deviation, calibration date, due date, temperature, relative humidity, calibration result (pass/fail), and remarks.

Calibration Label

• Instruments are uniquely identified by their calibration labels. Each label should summarize the calibration history of the instrument, containing the identification number, previous calibration date, the next calibration due date, and the calibration technician's signature.

Carrying Out Calibration

• Calibration should follow the appropriate SOPs. The "as-found" condition (accuracy of the instrument over the required range before calibrating/adjusting/repairing) is determined. If the "as-found" condition is outside the specified limits, a deviation is raised. If the calibration passes, a calibration sticker with the calibration date is affixed. If it fails, actions to repair/replace are taken. After successful calibration, the master instrument list is updated. Instruments should be calibrated before their expiry date. External parties may be used, but internal personnel must monitor them to ensure adherence to the facility's procedures.

Different Types of Standards

• Absolute/International Standards: These are the ultimate benchmarks against which all reference equipment is calibrated.
• Primary Standard: This is the primary reference used for calibrating other instruments. It's maintained at a national lab or within the company. It is typically more accurate than other standards.
• Secondary Standard: These are within a company and used for routine calibrations. They are typically more accurate than measuring standards
• Measuring Standard: These are used in everyday measuring and control by the company.

Maintenance of Calibration Equipment

• Proper storage and handling are crucial. Minimum temperature and humidity control in the calibration lab is required, along with the influence of other environmental factors like vibrations

Categorization of Instrumentation

• Calibration frequency varies based on usage patterns, process sensitivity, manufacturer recommendations, and prior calibration history. Instruments that have maintained calibration for more than six months likely don't need quarterly calibration. The frequency needs to be determined considering the operation of the process being monitored and the accuracy required. The frequency of calibration should be based on the process being controlled and the level of accuracy required. There are three categories of instrumentation.

Critical, Major, and Reference Instruments

• Critical Instruments: Affect both the process and product (e.g., temperature control in an autoclave); calibrated at least six monthly.
• Major Instruments: Affect either the process or product (e.g., balance in a dispensary); calibrated annually or more frequently.
• Reference Instruments: Don't affect the process/product; used as reference points (e.g., thermometer in a warehouse); calibrated on installation (and perhaps periodically).

Purchase of New Instruments

• New instruments require steps for identification, tagging, proper categorization (critical, major, or reference), recording the categorization and rationale, current calibration certificates (with accuracy, range, and expiry dates), traceability to national standards, and initial calibration if necessary.

Review of Calibration Programme

• The calibration program should be reviewed annually to ensure its continued appropriateness and effectiveness. The frequency of individual instrument calibration should be determined, taking previous calibration history into account. Standard operating procedures should be reviewed for suitability given the focal point of usage of some measurement devices.

Training of Calibration Technicians

• Calibration training programs should cover all personnel, including those calibrating and those reviewing the calibration data, to ensure complete understanding. Written training plans with thorough records of completed training will monitor skill levels. Refresher training is recommended annually to ensure standard procedures are kept up-to-date. New personnel should be trained on new instrument systems upon installation.

What is Maintenance?

• Maintenance encompasses any activity—tests, measurements, replacements, adjustments, and repairs—intended to retain or restore a unit to a specified state, enabling required functions. This includes all technical and management actions to retain (or return to) a device to its state for its functions. It covers repairing mechanical and electrical devices (or systems) which have become broken. It also includes actions that keep the system functioning normally to prevent arising problems.

Burdens Relevant to Maintenance

• Operators less able to conduct repairs themselves.
• Machine or product failures affecting company operations/profitability.
• Idle workers/facility leading to losses.
• Breakdown-related losses.

Principle Objectives of Maintenance

• Achieving product quality while satisfying customer needs.
• Maximizing equipment lifespan.
• Preventing safety hazards and minimizing interruptions.
• Increasing facility utilization to maximize production capacity while preventing breakdowns and minimizing production losses.
• Minimizing production loss from failures.
• Increasing reliability of operating systems.

Basic Concepts of Maintenance

• Reliability: System operates continuously without failure.
• Availability: System is ready to be used immediately.
• Maintainability: A failed system is repaired easily and quickly.
• Safety: A failed system doesn't lead to catastrophic consequences.

What is Failure?

• A system fails when it can't meet its promises or perform functions appropriately. Failure results from errors within the system. Faults are the causes of errors.
  • Transient Fault: Appears then disappears.
  • Intermittent Fault: Occurs, vanishes, reappears inconsistently.
  • Permanent Fault: Requires component replacement/repair for normal function.

Types of Maintenance

• Corrective (Break-down) Maintenance: Repairs are conducted after equipment failure.

• Preventive Maintenance: Proactive maintenance actions aiming to prevent future issues to ensure preventative repairs and maintenance.

  • Aims to prevent failure, or minimizes the effects of future failures. Includes:
    • Inspecting, lubricating, and performing repairs and overhauls.

• Predictive Maintenance: Condition-based maintenance. It uses ongoing data to estimate when equipment might fail.

• Schedule Maintenance: Maintenance tasks regularly scheduled. Includes inspecting, lubricating, and overhauling.