Kill a watt, how accurate?
Wanting to know just how much power the window shaker uses, I bought a Kill a watt. It's been to cold to test the AC but most things I have tested are under the rated watts. The 1875w hair dryer w...
Forum Discussion
Most devices the power draw rating is "Typical" and will vary with things like voltage, when it was last cleaned and so on.. that 100 watt light bulb might just be the odd man out.
to test you really need a calibration lab or at least a calibration bench.. I can design one for you easily enough
you need: a light socket, a board, a fuse holder (Cartridge type) some cord and that 100 watt lamp and a good, CALIBRATED multimeter.
Measure pull the fuse and bridge the socket with the meter on AMPS (AC)
Write it down.
Replace the fuse and measure volts from the fuse (Source side) to the other side of the socket. NOTE: Unlug the unit when removing or replacing fuse)
Write it down
Multiply, that is watts, a light bulb has a power factor of 1.0 so the Volt-Amps will be the same. Read the K-A-W at the same time you take the voltage reading.
to test you really need a calibration lab or at least a calibration bench.. I can design one for you easily enough
you need: a light socket, a board, a fuse holder (Cartridge type) some cord and that 100 watt lamp and a good, CALIBRATED multimeter.
Measure pull the fuse and bridge the socket with the meter on AMPS (AC)
Write it down.
Replace the fuse and measure volts from the fuse (Source side) to the other side of the socket. NOTE: Unlug the unit when removing or replacing fuse)
Write it down
Multiply, that is watts, a light bulb has a power factor of 1.0 so the Volt-Amps will be the same. Read the K-A-W at the same time you take the voltage reading.
