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.” ...

The color temperature of a light, measured in kelvins, is its most noticeable characteristic. A candle, at 1900 K, appears orange. Daylight, at 5500 K, is much whiter and bluer. A 5500-K bulb, however ...