Operational low range of power/water meters...

[Externet]

What is the typical operation limits of AC power meters ? Do they register -say 10 mA ?

 

Water meters are unresponsive to a drip, drip, drip... Vanes do not turn at very low flow. Is there a typical minimum ?

 

What does wear imply in them, -say ten years.

[John Cuthber]

What's the context here?

There are meters that measure a billionth of a milliamp or for which "drip drip" is their full scale.

[fiveworlds]

I would imagine how the meter was assembled would have an effect they won't all be the same.

[Externet]

Sorry, left out 'household utilities' metering.

[Endy0816]

Need the manufacturer info.

 

 

This gives a bit of detail on the different possibilities:

 

 

While other mechanical-type and static-type meters are limited in low flow registration due to the technology type or through the use of an electronic low flow cutoff, the Neptune T-10 – with its nutating disc technology - can detect leaks at flow rates below 1/32* of a gallon.

https://www.neptunetg.com/Water-Meters/Residential/T-10-Meter/

 

 

[John Cuthber]

unfortunately, this

"flow rates below 1/32* of a gallon"

doesn't mean anything.

[Endy0816]

heh, good catch. Mainly meant the different types/options mentioned though.

[Sensei]

What is the typical operation limits of AC power meters ? Do they register -say 10 mA ?

Are not you mixing units here?

Power P is in Watts W,

mA, Ampere, is unit of Current I.

 

10 mA with 230 Volts is 2.3 Watts... That would be quite a lot to "miss"..

 

https://en.wikipedia.org/wiki/Electricity_meter

 

Analog electricity meters are basically motors, that have disc spinning after applying to them current. Number of revolutions are read by device and displayed.

In their case, your question could be rephrased to "is there so little current which won't cause motor to spin?" (even after a day/week/month of observation)..

 

Plug say 1 Mega Ohm resistor to it, record initial settings, and check again after a day.

You will see whether there is difference, or not.

Edited April 2, 2016 by Sensei

[Robittybob1]

Need the manufacturer info.

 

 

This gives a bit of detail on the different possibilities:

 

https://www.neptunetg.com/Water-Meters/Residential/T-10-Meter/

 

 

they describe its abilities:

 

the Neptune T-10 – with its nutating disc technology - can detect leaks at flow rates below 1/32* of a gallon. If water is moving, the T-10 can detect it.

They give a low rate but describe it as a volume. Is that per minute or hour? A rate would need a time factor surely.

[Enthalpy]

Pity I've forgotten the figures, I worked on them all.

 

All meters standards I knew of (energy, gas, water, home, industrial... and they depend on the utility company) allow for, but don't impose, zero reading below some threshold. This threshold is lower than 10mA for a usual power meter. That is, the consumption of an "idle" or "powersave" mode computer, television set... is properly measured.

 

At water meters, drip drip will be measured by some constructions (membrane meters) and not by others (turbines likely not). Some turbines have tiny bearings almost like watches, a few have magnetic bearings.