CABT Equipment Maintenance and Troubleshooting 3 — Questions and Answers
Question 1: During a scheduled PM on an infusion pump, you discover the flow-rate accuracy is ±8% at 5 mL/hr. Most manufacturers specify accuracy within:
- ±1%
- ±2%
- ±5% (Correct answer)
- ±10%
Correct answer: ±5%
Most infusion pump manufacturers and standards specify flow-rate accuracy within ±5% of the set rate across normal operating ranges.
Question 2: A surgical electrosurgical unit (ESU) causes interference on the patient monitor in the same OR. The first corrective step is to:
- Replace the patient monitor
- Inspect and improve the ESU's return electrode contact (Correct answer)
- Install a notch filter on the monitor
- Relocate the patient monitor to another room
Correct answer: Inspect and improve the ESU's return electrode contact
Poor return-electrode contact forces stray ESU current through alternative paths, increasing electromagnetic interference; improving the pad contact is the first step.
Question 3: Which lubricant is generally recommended for O-rings in medical gas equipment?
- Petroleum-based grease
- Silicone-based lubricant (Correct answer)
- Lithium grease
- Petroleum jelly (Vaseline)
Correct answer: Silicone-based lubricant
Silicone-based lubricants are oxygen-compatible and are recommended for O-rings in medical gas systems; petroleum-based products are fire hazards with oxygen.
Question 4: A hospital bed's nurse-call function is inoperative after repairs. What document should the technician consult to verify wiring?
- The biomedical work order log
- The manufacturer's service/wiring diagram (Correct answer)
- The hospital formulary
- The Joint Commission survey report
Correct answer: The manufacturer's service/wiring diagram
The manufacturer's service manual and wiring diagram provides authoritative information on correct wiring, connectors, and signal paths for the nurse-call circuit.
Question 5: When inspecting a suction regulator, you note the vacuum gauge reads 0 mmHg even though the wall outlet is functional. The most likely fault is:
- Clogged collection canister
- Ruptured regulator diaphragm (Correct answer)
- Blocked float shut-off
- Faulty wall outlet check valve
Correct answer: Ruptured regulator diaphragm
A ruptured diaphragm inside the regulator prevents the creation of negative pressure, causing the gauge to remain at zero despite a working vacuum source.
Question 6: The biomedical technician is setting up a preventive maintenance interval for a critical-care ventilator used 24/7. Which standard is the PRIMARY reference for PM frequency?
- NFPA 70 (National Electrical Code)
- AAMI/IEC 62353 electrical safety standard
- Manufacturer's recommended maintenance schedule (Correct answer)
- The hospital's capital equipment budget cycle
Correct answer: Manufacturer's recommended maintenance schedule
The manufacturer's recommended maintenance schedule, documented in the service manual, is the primary reference for PM intervals for medical devices.
Question 7: Which test is used to evaluate the integrity of the insulation on a line-powered medical device?
- Ground continuity test
- Dielectric withstand (hipot) test (Correct answer)
- Ground leakage current test
- Isolation transformer test
Correct answer: Dielectric withstand (hipot) test
The dielectric withstand (hipot) test applies a high voltage across the insulation to verify it will not break down under stress.
CABT Equipment Maintenance and Troubleshooting 3
During a scheduled PM on an infusion pump, you discover the flow-rate accuracy is ±8% at 5 mL/hr.
Most manufacturers specify accuracy within: