CPT Equipment Operation & Maintenance 3 — Questions and Answers
Question 1: What is the function of the platen pressure gauge on a hydraulic press used in prosthetics?
- It measures ambient temperature in the press chamber
- It indicates the force being applied to the workpiece (Correct answer)
- It controls the speed of platen descent
- It monitors hydraulic fluid temperature
Correct answer: It indicates the force being applied to the workpiece
The pressure gauge shows the force applied to the workpiece, allowing the technician to stay within safe limits for the material being formed.
Question 2: A vacuum-forming machine fails to achieve the target vacuum level. Which component should be checked first?
- The heating element thermostat
- The vacuum pump oil level and intake filter (Correct answer)
- The frame clamp tension
- The plastic sheet thickness
Correct answer: The vacuum pump oil level and intake filter
Low vacuum is most often caused by a dirty intake filter or low pump oil, both of which reduce pump efficiency.
Question 3: Which procedure is used to verify that a torque screwdriver is calibrated correctly before use on prosthetic components?
- Compare its setting to a reference torque standard or calibrated tester (Correct answer)
- Tighten a sample screw until it strips, then back off one click
- Apply WD-40 and recheck the tension spring
- Set it to the highest value and work downward
Correct answer: Compare its setting to a reference torque standard or calibrated tester
Calibration is verified by testing against a known reference torque standard to ensure accurate fastener tightening.
Question 4: When using a rotary tool (Dremel-type) for finishing carbon fiber prosthetic components, which bit type is most appropriate?
- High-speed steel twist bit
- Diamond-coated or carbide burr (Correct answer)
- Standard aluminum oxide grinding stone
- Wire brush attachment
Correct answer: Diamond-coated or carbide burr
Diamond-coated or carbide burr bits are required for carbon fiber because its abrasive nature dulls standard steel quickly.
Question 5: After completing fiberglass lamination, how should the mixing cups and brushes be disposed of in a compliant US prosthetic lab?
- Rinsed with water and placed in regular trash
- Treated as hazardous waste per OSHA and local regulations (Correct answer)
- Burned in an outdoor fire pit
- Returned to the resin supplier for recycling
Correct answer: Treated as hazardous waste per OSHA and local regulations
Uncured or partially cured resin waste is hazardous and must be disposed of according to OSHA and local hazardous waste regulations.
Question 6: What maintenance step prevents rust formation inside the air tank of a compressor used for prosthetic lab pneumatic tools?
- Adding rust-inhibitor oil to the tank
- Draining condensate from the tank drain valve regularly (Correct answer)
- Coating the interior with epoxy paint annually
- Running the compressor continuously to keep air moving
Correct answer: Draining condensate from the tank drain valve regularly
Moisture condenses inside air tanks and must be drained regularly to prevent corrosion and contamination of air tools.
Question 7: Which measurement tool is used to verify the bore diameter of a prosthetic socket mounting hole to ensure correct fit of a pyramid adapter?
- Outside micrometer
- Digital caliper set to inside measurement mode (Correct answer)
- Steel rule
- Depth gauge only
Correct answer: Digital caliper set to inside measurement mode
A digital caliper in inside measurement mode accurately measures bore diameters to verify compatibility with pyramid adapter specifications.
CPT Equipment Operation & Maintenance 3
What is the function of the platen pressure gauge on a hydraulic press used in prosthetics?