Efficiency Issues in our Reviews

[Travis]

Originally Posted by Gabriel Torres

Yes, take a look on the Corsair HX850W review, there is some difference between the Brand Electronics and the Kill-a-Watt power meters:

http://www.hardwaresecrets.com/article/741

I decided to invest and buy a professional precision power meter. This equipment is very expensive (USD 700), however it will end up not only this whole mess, but also we will be able to fix the reviews and also check which power meter is wrong. Also, a professiona power meter allows calibration via computer, which is fantastic, so we can always check to see if the unit is not calibrated correctly. I am almost buying this unit:

http://www.bellnw.com/products/0587/

Thanks,
Gabriel.

A Weibo PF12xx costs much less (less than USD100) and I'm quite satisfied with it. Don't know how much a Voltech PM100 costs there.
That Instek is good, considering its precision under vey light load and its communication function with PC via RS-232 port.

[Gabriel Torres]

I've just ordered the Instek. Buying cheap models we will always face the same dilemma everytime a given power supply gives high efficiency. This Insteak model as precision of 0.02% and also allows calibration via computer, so we can always keep it 100% calibrated. Thus we won't face any more issues measuring efficiency, plus we will be, to the best of my knowledge, the publication with the most high-end equipment to measure AC power. Tools that cost USD 100 or less probably don't have a tolerance this tight and they can show wrong results (see the Kill-a-Watt vs. Brand Electronics difference).

I will keep you posted as soon as I get the new tool, hopefuly this will happen this coming week.

Cheers,
Gabriel.

[Gabriel Torres]

06/23/2009 5:07 PM PST Update: The new power meter has arrived today. I've just updated our methodology, please take a look. I will try to update our recent reviews with the numbers collected by the new instrument.