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I need to measure the accuracy of a mains power meter at around 1W.

How can I go about it?

Despite being clueless about electronics, I do have some a Tektronix PA1000 Single-Phase Power Analyser that I can use to measure the actual power consumption of whatever circuit I can come up with.

Once I am satisfied with that consistently consuming my 1W, I would then connect the power meter and check what values are read there.

Can anyone advise how to setup such a circuit? I can fall back on electrical engineers to help me build it, but I failed to get the advice to get going.

SamGibson
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Dan Schien
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If you can verify the power consumption with your power analyzer you don't really need a precise 1W load, right?

Just use a (240V rated) 52.9k resistor that will give you approximatly 1W at you oulet. Then measure simultaneously with your power meter and your power analyzer and compare.

But I think a warning at this stage is obligatory: If you don't know much about electronics, be very careful when working with mains voltage. Better ask someone with some professional training to assist.

jusaca
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  • Hi. Thanks. I'll suggest that to my colleagues right away. Can you by chance explain to me how you came up with that? Absolutely - I would not do this myself but ask my colleagues. – Dan Schien May 04 '21 at 08:46
  • It is just the easiest approach. If you have professional equipment to compare your measurement to, why bother to build a precision circuit yourself? – jusaca May 04 '21 at 08:48
  • Of course. What I meant was - how did the calculation go to arrive at 52.9k ohm? – Dan Schien May 04 '21 at 08:50
  • Ah, that is just from the formular that gives you power over a resistor: P = \$U^2 / R\$. So R = \$U^2 / P = (230V)^2 / 1W = 52900 \Omega\$ – jusaca May 04 '21 at 08:53
  • V²/R = power in a resistive load – tobalt May 04 '21 at 08:55
  • @tobalt Yes, sorry, I meant \$V^2\$. U is the symbol for voltage used in germany, for some reason... – jusaca May 04 '21 at 08:58
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    @jusaca I didn't mean to correct you. We merely commented at the same time. :) also maybe there is an explanation for the voltage symbol here: https://electronics.stackexchange.com/questions/99584/where-does-u-for-voltage-come-from – tobalt May 04 '21 at 10:35