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The reported energy on the source display as actueel gebruik is presented with two digits behind the decimal point/comma suggusting it is accurate as 1/100 th of a watt ...... it is misleading as an acutal reading.

If you increase the energy consumption you will see fixed values of the actual consumption like 1,80 - 3,94 - 6,08 - 8,22 - 10,35 Watt the source software is receiving a digital value in units of about 2,14W. It should make sense and using 2048 units to cover 16AmpX230V = 3680Watt range.

In case you measure a standby energy consumption of a device at 10,35 Watt (5 units) the real value may range from 8 till 12 Watt so the accuracy is about +/- 20%. Not in line with the 5% accuracy reporting
May be the circle is keeping a beter cumulative accuracy by changing the transmitted digits like for a bunch of 5 units followed by a 4 unit reading.

Would like to have some explanation of the reported accuracy ... special the reported 1% with +/- 0,2W (cumulative) and 5% +/- 0,5W on actual reading.


H.

most power meters have a rating, eg, 3% above 1000ws, 5% above 200ws and as much as 20% BELOW 35ws. if you wanted accurate meters, you need those scientific meters to measure accurately.

Actuele nauwkeurigheid5%, +0.5W / -2,5W
Cumulatieve nauwkeurigheid1%, 0.2W

Zie http://www.plugwise.com/sites/default/f ... 5_0309.pdf

My experiences on accuracy of the actual reading will be an accuracy of +/- 1 Watt. It will be no problem for devices with a consumption of more than 100 Watt but in case you want to monitor devices like controllers, transformers, actors, standby usage (range less than 10 Watts) it will not provide you with the right actual reading

For example I got a Home Control Box on a plug and the actual reading was most of the time 3,94Watt but sometimes going down to 1,80Watt. So displaying the actual readings with two digits behind the decimal point is not making too much sense.

The actual values are jumping by 2 Watt - see my other entry on this topic. Dont know if the plug is making a correction by reporting once in awhile a lower value (in this case the 1.80Watt) or if it was the energy measuring circuit.

The cumulative hourly reading was 4 Watt (on the graph a litlle less than 4 Watt) and the daily consumption should be 4x24 = 96 Watt but it was 92Watt. So it looks like the cumulative reading is accurate at +/- 1 Watt or 1% what is in line with the technical specifications.

Some explanation on how the software is handling the low energy consumption readings will be appreciated.

Henk

Hi Henk,

I can provide you are more specific explanation about the way the plug is reading the actual power, but later on. Right now I am at the point of heaving a short break (a week winter sport holiday ).

The thing I want to tell you all right now, that there will be a future firmware update that makes the actual power more accurate.

Any News about this new firmware with more accurate power readings?

Bump.

No News?