Meter Accuracy & Validation Audit
Verification that metering used for billing, recharging or regulatory reporting measures accurately — covering the meter itself, the current and voltage transformers feeding it, and the wiring in between, any of which can introduce error the meter cannot detect.
What this study establishes.
On-site accuracy verification against a reference standard at representative load points.
CT and VT ratio, polarity, phase association and burden verification.
Assessment of CT performance at actual load, where low-load operation is a common error source.
Wiring verification from instrument transformer to meter terminals.
Error statement per meter point with measurement uncertainty declared.
Correction factors or replacement recommendation where a point is outside class.
What the work covers.
Verification that metering used for billing, recharging or regulatory reporting measures accurately — covering the meter itself, the current and voltage transformers feeding it, and the wiring in between, any of which can introduce error the meter cannot detect.
Metering-class CTs lose accuracy at the bottom of their range, and an oversized CT operating at a small fraction of rating can introduce error well outside its class marking. Where load has fallen since installation, the CT rather than the meter is usually the problem.
What lands in your inbox.
On-site accuracy verification against a reference standard
On-site accuracy verification against a reference standard at representative load points.
CT and VT ratio, polarity, phase association
CT and VT ratio, polarity, phase association and burden verification.
Assessment of CT performance at actual load,
Assessment of CT performance at actual load, where low-load operation is a common error source.
Wiring verification from instrument transformer to meter
Wiring verification from instrument transformer to meter terminals.
Error statement per meter point
Error statement per meter point with measurement uncertainty declared.
Correction factors or replacement recommendation where a
Correction factors or replacement recommendation where a point is outside class.
How we run it.
Scope & data capture
We confirm the question the study must answer, agree the measurement or modelling points, and collect what the work depends on: meter and instrument transformer nameplate data and calibration history; safe access for reference measurement at the metering position; billing or allocation records showing the disputed or suspect.
Measurement & modelling
Engineers carry out the measurement and modelling on site and in software, under operating conditions representative of the problem rather than a single convenient snapshot.
Analysis against standard
Results are assessed against IEC 62053-21 and IEC 62053-22, IEC 61869-2 and IEC 61869-3, IEC 62052-11, with the assessment basis and any measurement uncertainty stated rather than implied.
Report & recommendations
You receive a signed engineering report with findings ranked by consequence, the reasoning behind each conclusion, and mitigation options costed so they can be acted on or deferred deliberately.
Assessed against the published limits.
Common questions.
Typically in one of these situations: billing dispute with a utility, landlord or tenant; energy balance does not close and metering error is a candidate explanation; meters have passed their calibration interval, or none is recorded. If none of these apply, the study is unlikely to be the right next step and we will say so.
To scope and run the work we need meter and instrument transformer nameplate data and calibration history; safe access for reference measurement at the metering position; billing or allocation records showing the disputed or suspect quantities. Where any of it is missing we can establish it on site, which changes the scope rather than blocking the work.
Primarily IEC 62053-21 and IEC 62053-22, IEC 61869-2 and IEC 61869-3, IEC 62052-11, OIML R46. The applicable framework depends on your connection agreement and jurisdiction, so we confirm which applies before measurement rather than after.
Ready to start the engagement?
Tell us about your site and the problem you are seeing. We come back with a fixed scope, a fixed fee, and a named lead engineer.