Very accurate power meter with extensive options

A power meter such as this one uses the "tracking" of standby power guzzlers and for determining consumption via long-term measurement. As the electricity meter in the house, so you have even in such an apparatus reliably and accurately the real power (W) - especially in the interesting little power range - are measured. Here the instrument of ELV can score! Even minimal loads, whether inductive or resistive, are already collected from 0.1W. Thus, this meter is ideal to measure typical standby power guzzlers such as radio, television, rechargeable toothbrush and razor, etc. individually. Simply plug the electrical appliance to be checked in the Energy Master and have the real power in watts is displayed. Electrical appliances that swallow without a sensible (!) Display, more than 1W in standby are nowadays hardly more to tolerate!

Another task of this type gauges is the metering of intermittent devices, such as refrigerators and freezers. Since these devices are only temporarily starts the power-absorbing compressor, inevitably the time aspect plays an important role. For such a measurement you need hold the Meter only the "clock" button for 4 seconds to erase the current memory and a new (long-term) to start measurement. All other values, for example, after a day measurement period, extrapolated for a week, will take a month and year easily accessed ("forecast"). - In contrast to an earlier power meter of ELV (EM800), with this current device not the duty ("ED" means of adjustable current threshold) to determine the consumer. Too bad, because it is precisely this feature would be of interest here: The operating time of the compressor in time and percentage.

The accuracy of the measurements I have compared with my modest means in various sizes with the meter BENNING MM 7-1 TrueRMS digital multimeter and am basically to come nearly the same results (deviation +/- 1%). This fits so!

As positive and negative at the same time, I see the following points:

- Up to 3 different flow rates and 10 different memory locations for the consumer to be measured are selected. Positive are the possibilities, rather idle operation ... at least if one uses the device only occasionally! Setting options and retrieve measurement results or calculations, is difficult to achieve without the manual.

- Genial is the sensationally low closed power consumption, even with the active illumination is only ~ 0.4W. Here is also the same criticism, since the energy-efficient LED lighting for the display is active only after pressing a button!

- The Energy Master Profi of ELV feeds up to 30 minutes, even without hanging on the power grid, by means of a built-in double-layer capacitor (GoldCap) the unit with power, allowing the operator. But even this, a little criticism: There are not all accessible - this sense does not open up to me - and the display lighting remains off even after pressing a key. (All data will of course after about 30 minutes, permanently retained in memory.)

Overall, one can thoroughly recommend the device, in particular due to the accurate measurement of small loads! For occasional use, however, you should always have the manual handy ... as I would have liked a more thorough operation. A remote control and display section would be the icing on the cake. ;-)

Addendum October 2013:
The magazine c't in issue 21/2013 Devices from this series, as well as a kit tested, and found a very high measuring accuracy.

Tip: Compare prices (in ELV currently 49.95 dollars, as did Kit 39,95)!