Which of the following is NOT a recommended safety practice in instrumentation labs?

• A. Touching live circuits to verify voltage
• B. PPE and proper grounding
• C. Using fuses and power cords in good condition
• D. Following supervisor instructions and locking out hazards

Answer: (A)

The main safety idea here is that live electrical parts must not be touched. Work in instrumentation labs should be done with circuits de-energized or properly isolated, using rated PPE, proper grounding, and verified lockout/tagout practices to prevent unexpected energization.

Touching live circuits to verify voltage is not safe because it creates a direct path for current through your body. Even when you think a circuit is at a harmless level, hidden energy, capacitors, or faults can deliver a dangerous shock or cause an arc flash. Your body can become the conductor, leading to electrical shock, burns, or more severe injury, and you might inadvertently energize other parts of the circuit or equipment.

On the other hand, PPE and proper grounding protect you by providing insulation and a safe reference, keeping fault currents away from you. Using fuses and ensuring power cords are in good condition reduce the risk of overheating, fires, and unexpected energization. Following supervisor instructions and locking out hazards ensures that everyone works under controlled, trained procedures and that circuits cannot be turned on while someone is working on them.

So the unsafe practice is touching live circuits; the rest are standard safety measures that help prevent injury and equipment damage.