Before using a multimeter to check voltage on a breaker, what should you do?

Checking a multimeter with a known power source before using it to check voltage is an essential step to ensure the accuracy and reliability of the measurements you will be taking. This practice allows you to confirm that the meter is functioning properly and that the readings it provides are valid.

Using a known power source helps to verify whether the multimeter's display accurately reflects the voltage level, which is crucial for effective troubleshooting and diagnostics in electrical systems. If the meter shows an unexpected reading when connected to a known source, it may indicate a malfunction or a battery issue that needs to be addressed before proceeding.

By performing this check, you can prevent potential misinformation while assessing a breaker’s voltage, ensuring that any decisions made based on the multimeter's readings are grounded in accurate data. This practice enhances personal safety and promotes adherence to best practices within electrical work.