Testing emontx 3CT and voltage

Notes from a quick test (not comprehensive) of real power accuracy and precision using emontx with 3 CT's, AC-AC Voltage adapter.  Here are the results:

Reference meter 452W

emontx: plot01,  plot02

Reference meter 51W

emontx: plot03

Reference meter 2065W

emontx: plot04plot05

Reference meter 2439W

emontx: plot06plot07

Install KST2: sudo apt-get install kst2

KST Plot config file 3CTVoltage.zip


Error calc sheet

Without additional calibration the maximum error was 41W @ 2398W

With extra calibration is should be possible to get +-7W error

A maximum percentage error of 14% @ 51W was recorded however most precentage errors where below 1% for the readings taken (take a look at the attached spreadsheet for more info).

It could have been that the 14% error was a erronous reading. More datapoints would be needed to properly test.


Maximum standard deviation (sigma) recorded in above tests was 4.51W @ 2400W