Submitted by TrystanLea on Tue, 17/01/2012 - 13:24
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:
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.
Precision
Maximum standard deviation (sigma) recorded in above tests was 4.51W @ 2400W
Testing emontx 3CT and voltage
Submitted by TrystanLea on Tue, 17/01/2012 - 13:24Notes 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: plot04, plot05
Reference meter 2439W
emontx: plot06, plot07
Install KST2: sudo apt-get install kst2
KST Plot config file 3CTVoltage.zip
Error
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.
Precision
Maximum standard deviation (sigma) recorded in above tests was 4.51W @ 2400W