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%
100
UUT
REF
REF
I
I
Error
%
I
u
1
REF
n
n
UUT
I
IGAIN
IGAIN
I
u
%
100
UUT
REF
REF
V
V
Error
%
V
u
1
REF
n
n
UUT
V
VGAIN
VGAIN
V
u
Calibration Procedures
3.3
Calibration Procedures
3.3.1 Calibration of AC and DC Parameters
To calibrate the ac and dc parameters:
1. Calibrating VGAIN
(a) Set to No / Lowest possible load.
(b) Set VIN to line voltage.
(c) Calculate the value for VGAIN with
where
•
VGAIN
n+1
is the new voltage calibration factor
•
VGAIN
n
is the original voltage calibration factor
•
V
REF
is the reference meter voltage reading at the voltage set for VGAIN calibration
•
V
UUT
is the unit under test voltage reading at the voltage set for VGAIN calibration
(2)
Or if percentage error is used (as with the provided calibration software):
(3)
(d) Write and apply the calibrated VGAIN.
2. Calibrating IGAIN
(a) Set VIN to line voltage.
(b) Set to High / Highest possible load.
(c) Calculate IGAIN value with
where
•
IGAIN
n+1
is the new current calibration factor
•
IGAIN
n
is the original current calibration factor
•
I
REF
is the reference meter current reading at the current set for IGAIN calibration
•
I
UUT
is the unit under test current reading at the current set for IGAIN calibration
(4)
Or if percentage error is used (as with the provided calibration software):
(5)
(d) Write and apply the calibrated IGAIN.
20
Calibration Techniques
SLAU587 – August 2014
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