Polygraph Machine Components

• Other parts of a polygraph machine:

Polygraph Components and Functions

• Pen lifter: Raises or lowers pens in three positions.
• Program pacer: Programmable cueing device for question and answer spacing.
• Paper tear bar: Provides a cutting edge for convenient chart removal.
• Foam pen hold down: Keeps the pen in place during instrument transport.
• Attach compartment: Storage for all forms of supplies.
• Mechanical Pneumo Module: Located inside the instrument and receives reactions detected by the corrugated tube and moves the pen to record the reactions.
• Galvanic Skin Response Module: Located inside the instrument; receives reactions detected by finger electrodes and moves the pen to record the reactions.
• Mechanical Cardio Module: Located inside the instrument; receives reactions detected by the cuff and moves the pen to record reactions.
• Paper storage compartment: Holds two spare rolls of chart paper and supplies.
• AC power receptacle: Connects power cords; International standard design for easy cord replacement.
• Power switch and circuit breaker: Applies power, has a built-in resettable circuit breaker which protects the instrument and eliminates the need for fuses; reset by simply pressing off and then on again.
• Chart drive roller lever: Lifts chart drive roller for paper changes and chart removal.
• Power analyzer: Automatically indicates if wall outlets are properly wired and grounded for proper instrument operation and subject safety.
• Stimulus marker: Marks significant events on the chart.
• Sphygmomanometer dial: Reads operating pressure of cardio channels.
• Pneumo 1: Pneumatic connection for upper pneumograph.
• Pneumo 2: Pneumatic connection for lower pneumograph.
• Cuff: Pneumatic connection for cardio channel subject cuff tubing.
• Pump: Pneumatic connection for the hand pump used to inflate subject cuff.
• GSR Input Connector: Accepts plug from GSR subject attachment cord.
• GSR mode switch: Selects the operating mode for GSR Channel Manual or Automatic.
• Mechanical Cardio Switch: Disengages the mechanical cardio module from the pneumatic system for low pressure electronic cardio operation.
• Centering control knob: Positions pen on chart; rotating clockwise raises pen and counterclockwise lowers it.
• Sensitivity control knob: Determines tracing size (amplitude); rotating clockwise increases size and counterclockwise rotation decreases it.
• Resonance control: Decreases the amplitude of the cardio tracing and is used to sharpen the diacrotic notch.
• Vent: Performs venting function on the pneumatic system; vent down closes the system and makes it non-operative, and vent up opens the system and makes it ready for use.

Polygraph Inking Process

• Remove cap and capillary tube from bottle.
• Extract ink from the supply bottle using the provided filler pipette/dropper.
• Fill the ink container to approximately ¾ full, being cautious not to overfill.
• Spillage is more likely during transit if the bottles are overfilled.
• Grasp the bottle and tighten it using your free hand to rotate the bottle.
• Squeeze the bottle until the ink is forced to the end of the pen.
• Loosen the caps again by rotating the bottle ¼ open.
• Release bottle pressure.

Cleaning Polygraph Pens

• Remove the pen with capillary tube and ink bottle, without disconnecting the total inking system to prevent stretching of the capillary tube seal or the seal of the ink bottle.
• Remove the ink bottle cap and pour out any excess ink.
• Fill and rinse the bottle cap, pouring out excess ink.
• Fill with clear water, apply pressure as in the inking process until clear water flows from the pen tip.
• If tap water has high mineral content then flush the pens a final time with distilled water or alcohol.