While using a digital multimeter to diagnose electrical problems on customers’ equipment, I frequently hear the comment, “I’ve got one of those multimeter things, but I never learned how to use it.” ...

When you measure a voltage, how do you know that your measurement is correct? Because your multimeter says so, of course! But how can you trust your multimeter to give the right reading? Calibration ...

If your goal is to save on electricity, you must first measure the ac current flowing through your appliances. The formula for power is the product of the ac line voltage and the measured current.