What safety precaution should be taken when using a voltmeter?

When using a voltmeter, ensuring that the probes are connected to the proper voltage range is essential for both accuracy and safety. This precaution helps prevent damage to the voltmeter itself from over-voltage conditions, which could occur if a low-range voltmeter is connected to a higher voltage source. Correctly setting the voltage range also reduces the risk of electric shock to the user, as the meter will operate within its designed parameters.

By selecting the right voltage range, users can obtain accurate readings, which is crucial for diagnosing electrical faults or ensuring that circuits are functioning correctly. This practice also promotes safe operation, as voltmeters can be damaged or rendered unsafe if they are used outside of their specified limits. Choosing the correct voltage range is a fundamental safety measure in electrical testing.