On Fri, 31 Jul 2020 11:24:31 +0100, Pamela
wrote:

Is this sort of plug-in power meter suitable for measuring a desktop PC with
a switched mode power supply?

I bought something similar a long time ago but found it was giving misleading
readings. Are these better now?

https://www.amazon.co.uk/Consumption.../dp/B07FZZ17ZY

I don't think they are particularly sophisticated (and I have a couple
that look exactly like that) and may have difficulty reading much
other than a near resistive load with any real / absolute accuracy.

However, I find them fine as a general indicator of power consumption,
especially when comparing like with like (SMPSU powering a Raspberry
Pi or a PC etc).

I can't think if I've ever measured something that was actually rated
that didn't also have variables / additions that could have impacted
the result or if I have, I didn't note that it was far away from what
was stated (suggesting they were accurate and the meter also
reasonably so).

I think the last things I measured / compared were a RPi NAS, a
slimline Shuttle PC running as a NAS, a Synology NAS and a Buffalo
Terastation NAS and the results were about what I expected. As
mentioned though, you often had to take several readings with the HDD
idle, unit sleeping etc.

Cheers, T i m