Mains Frequencies and Voltages
While I have included the 121GW and the data I really wanted to have a proper look at the relative accuracy of a Valhalla 2703 AC Calibrator I have picked up during the year. I have run tests over 50 and 60 hz in the ranges of 100-130V and 220-250V today so this covers the majority of mains used in the world.
Other than spot checks on meters I haven't run a proper series through the Valhalla so time to start and figure out if it is in or out of spec. and look at if it needs a tweak. I will run some higher frequency tests and bigger voltage ranges against the 34401a but unless someone wants anything specifically on the 121GW I won't most likely get any additional data. The 121GW works within spec on limited testing to above 5kHz as claimed as I have done some other testing prior.
Doing this for me was to improve confidence in mains logging I have done from time to time on the 121GW and to get a better idea of the accuracy of the data. Not metrology grade results by any means but to give a reasonable level of confidence.
Valhalla 2703 stated accuracy +- 0.03% reading +0.03 range
Agilent 34401a accuracy +- 0.06 reading +0.03 range (two ranges used <120 and <750)
121GW accuracy +- 0.3 + 10 counts (0.1V in these tests I have manually added it to the errors as parsing data is a PITA)
I have included columns with calculated errors for the readings from the Specifications and while they sit well inside that there appears to be a minor issue with the Valhalla outputting consistently low by circa 0.1V/100V in this sort of frequency range. Voltage Steps of 2V are very consistent against both the meters. If a correction of that 0.1/100V was done the absolute error drops dramatically. Man with two clocks problem but I only have one good clock
Call it the 121GW on mains around the world way better than spec regardless