Calibrating a Stanley Power Meter EM100

So I've got one of these Stanley EM100 power meters. It works fine, but it's got a completely inaccurate calibration.

I put it on my fridge and it was telling me that it only costs $17 per year. Either my fridge is awesome or something's quite wrong.


Hooking it up to a Kill a watt is pretty easy as it redirects the plug in the rear to a socket on the side of the EM100.

After a few days, it's pretty easy to find what the multiplier should be and factor that into the cost per kilowatt hour. The only thing is that the EM100 only goes up to 0.50 per kwh, so if electricity goes up much more I won't be able to do this. So instead of say .12 per kwh, I enter .46 per kwh to get correct cost readings.




I've actually got it hooked up to 2 different kill a watts, one of the older ones and a newer kill a watt EZ.

It's been hooked up for 825 days on the EM100 calculating a cost of $57.67 per year, I wonder how many days the EM100 can keep track of?


The kill a watt EZ has gone over 9999 hours and won't display anything timewise except a flashing 9999.

The Stanley EM100 is kind of neat in that it has a small battery so if the power goes out you don't lose your readings. The Kill a watt EZ has a battery back up as well, but the old kill a watt will reset itself in the case of an outage.