Oregon Scientific ESM200 wireless energy control

[Bwired]

Oregon is also stepping in to the energy control business with the wireless EMS200
suitable for 3 phase en sending data every 6 seconds, it's on the 433 MHz so there is a change that this signal is received by Rfxcom.

http://www.elv.de/Oregon-Scientific-Fun ... ail2_27879

89587_F03_GeESM200.jpg (32.13 KiB) Viewed 6492 times

89587_F05_GeESM200.jpg (19.5 KiB) Viewed 6492 times

[yjb]

Looks to me as a lot cheaper when compared with RFXcom, however......

How is Oregon doing the measurements, it appears to me that they are only measuring the induction on each wire (which gives you a current indication, Ampere). Without knowing the exact Voltage level, the actual power utilization will be a wild guess and can easily be off 5-10% (+/-). In the long term this will probably equal out, but short term measurements will not be exact.