Q: Rambam hospital in Israel has light power saving project with contractor "T.P.V".
The contractor replaces Lighting fixtures, old noun fluorescent light fixture to L.E.D light fixture.
The old noun fluorescent light fixture with magnetic ballast has cos ph. 0.7 to 0.8.
The contractor measured the power by this method:
"METER SPECIFICATIONS
Power will be measured by a freshly calibrated wattmeter owned by the contractor. The model chosen is
Fluke 287 True RMS AC/DC Clamp Meter with LH41A AC Current Clamp Probe. The meter directly measure
Voltage and current. The power consumption is calculated simply multiply the 2 values."
Fluke 287 True RMS AC/DC Clamp Meter with LH41A AC Current Clamp Probe is not watt meter!!
The measurement with this method will be in volt-amperes not in watt, the value will be bigger than if it will be measure with watt meter.
Can you give the right instruction or recommendation for the measurement?
Thank you very much.

A: IPMVP Core Concepts, Section 6.2.2.1 Electricity Measurements, recommends utilization of a true RMS meter to accurately measure wattage, for loads that are not purely resistive. Therefore the statement above is correct - voltage, amperage and power factor need to be measured with a true RMS meter to accurately measure wattage.