User’s Manual Smart Digital Power Meter
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9.3 Notice Matters for Calibration
Verification and Calibration
The precision of standard meter should over a grade than measured meter, standard source should be
stable. All the instrument power on 15 minute and wait it to stabilize, and then slowly adjust the output
voltage or current of the standard AC source. Observing the standard meter to reading out the required
value precisely, record the data of the standard meter and measured meter after the data is stable, and
calculating the measuring error value to judge whether is within the error range. The requirements of
environment temperature of verification and calibration as the following table.
Item
Reference Value or Range
Reference Value or Range
Environment temperature
℃
23
±5
Environment humidity % RH
45
～
75
Barometric pressure KPa
86
～
106
AC power supply voltage V
100
～
240
±2%
AC power supply frequency Hz
50
±1%
Ac power supply waveform
Sine
ß = 0.05
External electromagnetic field
interference
Avoid
Ventilation
Well-condition
Sunlight
Avoid direct sunlight
Notes
：
The inspect equipment should meet the specifications of the regular metrological verification,
measurement period is one year.
Wiring scheme of verification and calibration as shown in the following figure.
