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Thread ID: 107763 2010-03-01 05:41:00 power meter for PC Active (15098) Press F1
Post ID Timestamp Content User
862669 2010-03-02 09:21:00 One wonders how accurate these cheap meters are when it comes to measuring the current waveform of a switch mode power supply. True RMS? rumpty (2863)
862670 2010-03-02 09:44:00 Neither could I find specifically whether it measured power factor, though there were suggestions that it did.

I thought power factor didn't matter in a residential scenario? (if you are talking about the electricity bill)
Agent_24 (57)
862671 2010-03-02 18:52:00 I thought power factor didn't matter in a residential scenario? (if you are talking about the electricity bill)

Well, households have quite a few motors running all the time, fridges, air conditioners, heat pumps etc, so it would be an advantage to know the power factors.
Terry Porritt (14)
862672 2010-03-02 21:06:00 Why is it an advantage though? For the purposes of this meter - finding the cost of running a PC - I would have thought power factor wouldn't matter.

As far as I know, only industrial customers are charged on power factor. Or have I got it wrong?

I admit I do not know much about this, having only picked up what I know from reading websites about "Power factor correction" circuitry in PSUs and why it (apparently) is just a marketing point and serves no real useful purpose in the context of home use...
Agent_24 (57)
862673 2010-03-02 21:47:00 Why is it an advantage though? For the purposes of this meter - finding the cost of running a PC - I would have thought power factor wouldn't matter.

As far as I know, only industrial customers are charged on power factor. Or have I got it wrong?

I admit I do not know much about this, having only picked up what I know from reading websites about "Power factor correction" circuitry in PSUs and why it (apparently) is just a marketing point and serves no real useful purpose in the context of home use...

I meant advantageous in the sense it would be interesting to know the power factor for different appliances, not that there is anything that can be done about it :)
On the practical side, if the meter does not measure power factor, as I believe some such meters do not, then the power readings and the cost calculations will be in error by around 2 percent or so.

This may be less than the accuracy of the meter, so may not be worth worrying about unless there is a device with a very poor power factor.

So I agree with you.
Terry Porritt (14)
862674 2010-03-03 04:52:00 Thanks Terry and others for your advice and contributions to this thread.:clap Active (15098)
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