Wattmeters
The Laboratory offers calibration for single-phase wattmeters at fixed frequencies of 50 Hz, 60 Hz or 400 Hz, and in the power factor range of unity to 0.5 leading or lagging.
Wattmeters will be calibrated by direct comparison method against the Laboratory standard wattmeter with phantom load. The theoretical power measuring range is 37.5 W to 6 kW and the maximum test voltage and current are respectively 300 V and 20 A.
Basic calibration of a wattmeter will include tests at rated voltage and frequency with 5 different current settings on the current range (unity power factor). For multi-range wattmeters, additional measurements will be made for all combinations of rated voltage and current ranges.
Calibration charges
| Fee in HK$ | |
|---|---|
| Calibration of a wattmeter at rated voltage with 5 different current settings on one current range (at one frequency and one power factor). |
$2400 |
| Additional measurement for each combination of rated voltage and current ranges for multi-range wattmeters (same frequency and power factor as in 1. | $450 |
| Additional service as in1 but at a different frequency or power factor. | $1190 |
| Additional service as in 2 but at the same frequency or power factor as for 3. | $450 |
