Test equipment can cost a fortune for the hobbyist or casual tinkerer. Fortunately there are a few exceptions like digital thermometers and Digital voltmeters for checking b
atteries. Sometimes you can get items like that in the $10-30 range where commerical equivalents are in the $300-$2000 range.
Fortunately, the Kill A Watt consumer wattmeter is one such device like that. This little gem cost $17 to $30 online and does 90% of what my Valhalla Scientific wattmeter at work does, which cost $1000 in the 90's.How does it work? Great! I bought two and was very pleased with the results. Both measured within 1% of my Valhalla Scientific wattmeter at work. Admittedly, this model only works on 120VAC (not 230VAC) up to 15A and 125VAC maximum and is powered by the source it is measuring. It does measure real power accurately and even has long term averaging of rms power draw to calculate KWh over a period of time. It also measures line frequency, power factor and VA values. To me, it's biggest advantage is handy portability. You can quickly stick it inline to see what a TV, stereo, microwave, EFL lamp or ac wall charger power supply draws. The owner's manual may be downloaded here:
