ZES ZIMMER LMG450, Руководство пользователя

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Miscellaneous LMG450
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12.3 Maintenance
12.3.1 Calibration
With this precision power meter you have a high end measuring instrument. But you can only
take advantage of it’s performance, if the instrument is well adjusted and calibrated. Especially
with the calibration of third party labs there are very often unnecessary problems. If you let the
calibration made by any third party calibration lab, please watch following points:
•
The reference instruments might have not the required accuracy, especially for active AC
power.
A very common error is, that reference sources, which some companies call ‘calibrator’
have not the necessary accuracy to calibrate this instrument. The calibrators are very useful
for many hand held multimeters, but are often worthless when calibrating active power. A
common candidate for this error is the Fluke 5500A calibrator.
Please keep in mind, that the reference instrument should be at least 3 times more accurate
than the device under test. If not, the precision power meter calibrates the so called
calibrator!
•
The reference instrument may be traceable for voltage and current, but it is very rare, that
it is traceable for active AC power with the required accuracy. Nevertheless it is common,
that calibration labs calibrate active power if only voltage and current are traceable. This
happens very often in the context of national calibration services like DKD, UKAS, …
Here it happens regular, that voltage and current are accredited, but not the active power.
So this protocols are worthless for active power!
If a calibration is performed by any third party lab, at least following points should be
calibrated to ensure a proper function of the instrument:
•
Voltage and current of all ranges at a frequency near to 50Hz.
•
A representative selection of voltage/current range combinations to ensure a proper power
reading
The ZES ZIMMER calibration service offers a traceable calibration of all relevant parameters
and meets the requirements of IEC17025. Our active power calibration is directly traceable to
PTB (Physikalisch Technische Bundesanstalt in Braunschweig).
A further advantage of our calibration service is, that for the case of a service there are no
additional shipping costs and time delays.