Latest release and accuracy


Release 02_02_29 has been out for a week now. At least that’s how long I’ve had it running in my own home system. No issues, has been running straight for six days. A few periods of higher than normal feedback posting to Emoncms, but those seem to coincide with remarks about slowdown from other users, and the errors are the type that wouldn’t just go away on their own if it were on the IoTaWatt end.

This new release contains some improvements to the phase correction algorithms and correction factors for various CTs. This is the mechanism that compensates for the time delays in the CTs and VT that impact the ability to get the true picture.

To get a sense of the accuracy, I have installed a couple of revenue grade (1% EKM) meters on two appliances in the house: My heatpump which is working pretty hard these past few months and has a power factor of .86. The other is my resistance hot-water tank which works pretty hard this time of year and is unity power factor. I also have a new electronis service meter that I think is pretty accurate, although only reads in whole Kwh.


Since early winter, Both the Heat-Pump and Water Heater loads vary significantly less than 1% from the meters. With the improved phase and calibration, results are at least as good. The service meter tracking is a separate IoTaWatt in an outbuilding and had an interruption after a power failure when I didn’t reconnect the USB power for a day after using the generator. In the last 7 days it is about 0.5% from the meter.

I’ll try to report back on this regularly.