Using an Oscilloscope: Part II. Making Measurements: Section 7. SAFETY

Before you make any oscilloscope measurement, remember that you must be careful when you work with electrical equipment. Always observe all safety precautions described in the operators or service manual for the equipment you’re working on.

Some general rules about servicing electrical equipment are worth repeating here. Don’t service electrical devices alone. Know the symbols for dangerous circuits and observe the safety instructions for the equipment you’re working on. Don’t operate an electrical device in an explosive atmosphere. Always ground the scope to the circuit, and ground both your scope and the circuit-under-test. Remember that if you lose the ground, all accessible conductive parts — including knobs that appear to be insulated — can give you a shock. To avoid personal injury, don’t touch exposed connections and components in the circuit-under-test when the power is on. And remember to consult the service manual for the equipment you’re working on.

Then there are few rules about the scope itself: To avoid a shock, plug the power cord of the scope into a properly-wired receptacle before connecting your probes; only use the power cord for your scope, and don’t use one that isn’t in good condition (cracked, broken, missing ground pin, etc.). Use the right fuse to avoid fire hazards. Don’t remove covers and panels on your scope.