How accurate are cheap CT meters

[Teddy Lop]

A client of mine wishes to verify the accuracy of some meters, I was thinking something like the below could be fitted to a 13a plug and moved around more easily than a conventional meter, would you expect reasonably accurate performance from something like this?

Amazon.co.uk

 

[Avo Mk8]

A client of mine wishes to verify the accuracy of some meters, I was thinking something like the below could be fitted to a 13a plug and moved around more easily than a conventional meter, would you expect reasonably accurate performance from something like this?

Amazon.co.uk

I wouldn't be confident about the accuracy of that. Might be OK but how do you know?

Firstly I suspect you would be better off with a split-core current transformer, so you can clip it on the cable of an existing installation, and secondly I would suggest buying something built to a standard - eg meter accuracy standard "MID".

I'm not necessarily recommending the thing below, but it's illustrative of the sort of kit built to a standard and it would be accurate.
(You would need to be able to plug it into the mains, unlike the battery powered instrument you show, but I guess that shouldn't be too big a problem)

OB115-MOD 100A, Mid Approved, DIN Rail, CT Operated, RS485, Bi-Directional DIGITAL METER

OB115-MOD 100Amp CT Smart Meter INCLUDES: Solid/Split Core CT sensor, 333mV ac input 100A. ● MID approved with module B & D certification. ● Bidirectional energy metering 1 DIN modules,230V AC 50/ 60Hz.● Display of Voltage, Ampere, kW, PF, Hz, +kWh,-kWh,ΣkWh ● Total energy usage...

owen-brothers.com

 

[Avo Mk8]

Or you could perhaps hire (it's a bit expensive to purchase ) something made for the job!

AC CLAMP POWER METER CM3286-50 | Hioki

Measures voltage, current, power, power factor, phase angle, reactive power or frequency. Detect Electricity Theft and Meter Tampering.

www.hioki.com

+/- 2% accuracy

 

[James]

A client of mine wishes to verify the accuracy of some meters, I was thinking something like the below could be fitted to a 13a plug and moved around more easily than a conventional meter, would you expect reasonably accurate performance from something like this?

Amazon.co.uk

normally to check the accuracy of a meter you would use a load bank.
they are available to hire.
they should come with a calibration certificate to show they are accurate.

Home - LoadBank 4 Hire

Loadbank hire from 20kw - 2MW. Flexible hire terms and trailer mounted for difficult locations like under ground car parks. Various lengths of suitably rated cables available and are fitted with Litton connectors for ease of the user. Can be delivered to site with an engineer who will lay the...

loadbank4hire.co.uk

 

[Teddy Lop]

I wouldn't be confident about the accuracy of that. Might be OK but how do you know?

Firstly I suspect you would be better off with a split-core current transformer, so you can clip it on the cable of an existing installation, and secondly I would suggest buying something built to a standard - eg meter accuracy standard "MID".

I'm not necessarily recommending the thing below, but it's illustrative of the sort of kit built to a standard and it would be accurate.
(You would need to be able to plug it into the mains, unlike the battery powered instrument you show, but I guess that shouldn't be too big a problem)

OB115-MOD 100A, Mid Approved, DIN Rail, CT Operated, RS485, Bi-Directional DIGITAL METER

OB115-MOD 100Amp CT Smart Meter INCLUDES: Solid/Split Core CT sensor, 333mV ac input 100A. ● MID approved with module B & D certification. ● Bidirectional energy metering 1 DIN modules,230V AC 50/ 60Hz.● Display of Voltage, Ampere, kW, PF, Hz, +kWh,-kWh,ΣkWh ● Total energy usage...

owen-brothers.com

That's probably a better option thanks

I intented split core anyway, the idea is to leave him something he can move around himself subject to there being a socket