Benefit of optical pulse sensor

Hi everybody,

Just delving into the Openenergy Monitor and looking to make a purchase soon. I will use it for energy and solar monitoring.

I just wanted to know, what is the benefit of the optional optical pulse sensor and do people find it necessary to get an accurate picture of their electricity consumption and generation if the CT clamps are in place?

Kind regards,


The pulse monitor monitors pulses from your supplier’s meter. By definition, that is 100% accurate, even if it is not! But you only get pulses when you are importing energy, so they cannot tell you what you export. (That is for most meters, there are exceptions - I recently heard of a meter that emitted pulses when both importing and exporting.)
The principal use, if you have c.t’s, is for calibration and as a check on the imported energy calculation.

Thanks for that answer Robert.

One other minor question. I see that there’s an option for a temperature sensor in the emonPi bundle. What again is the purpose for this? Is it to be used as a bit of a failsafe in case the electricity meter catches on fire, or just for general information? I have my own external temperature sensor outside so if it’s just for general info I won’t worry about it.

Thanks again.

It’s for sensing any temperature that you want to sense! Or more precisely, temperatures; because you can connect many sensors to the OneWire bus. People use it for room, environmental, hot water, solar collector temperatures, etc, where a wired solution is preferred. Or use the emonTH where you want a battery-powered wireless temperature & humidity monitoring point.

So in your case, you might want to forget it.