Before taking a measurement with a multimeter in ohmmeter function, what is the first step?

The first step before taking a measurement with a multimeter in ohmmeter function is to touch the black and red leads together to zero the meter. This process is essential because it calibrates the meter to account for any resistance in the leads themselves, ensuring that the measurement taken reflects only the resistance of the component or circuit being tested, not the added resistance from the leads. By zeroing the meter, users can achieve a more accurate and reliable reading.

Calibration in this way helps in attaining precision in measurements, especially when working with low resistances where the meter's internal resistance could significantly affect the outcome if not accounted for. This step is fundamental and part of best practices in using a multimeter effectively. It lays the groundwork for obtaining accurate resistance measurements throughout the testing procedure.