Local Low Range Frequency Calibration - Cal Power TrueWave TW5250 Service Manual

SERVICE MANUAL
Calculate the gains and offset for the phase being calibrated:
GAIN1 = (MEAS1 – MEAS2) / (RDGN1 – RDGN2)
GAIN2 = (880.0) / (MEAS1 – MEAS2)
OFFSET = GAIN2 * MEAS1 – 440.0
Update the TW calibration registers by sending the following GPIB strings:
CAL{1,2,3}:MEAS:REM:HIR:VOLT:GAIN GAIN2
CAL{1,2,3}:OUTP:REM:HIR:VOLT:GAIN GAIN1
CAL{1,2,3}:OUTP:REM:HIR:VOLT:OFFSET OFFSET
Reset the TW's output to a safe condition:
SOUR{1,2,3}:VOLT:OFFSET 0.0
OUTPUT OFF

3.11 LOCAL LOW RANGE FREQUENCY CALIBRATION

Connect the TW output to the DMM. Set the DMM up for auto–ranging AC voltage.
Set the TW into AC coupling, local sense, 40 Hz, 120V, and low range by sending the
following GPIB strings:
OUTP:COUP AC
SOUR:VOLT:RANGE LOW
SOUR:SENSE LOCAL
SOUR:FREQ 40.0
SOUR{1,2,3}:VOLT 120.00
Close the TW's output relay:
OUTPUT ON
Wait for the DMM to settle and record the voltage as MEAS1.
Set the TW to 80 Hz.
SOUR:FREQ 80.0
Wait for the DMM to settle and record the voltage as MEAS2.
Set the TW to 160 Hz.
SOUR:FREQ 160.0
Wait for the DMM to settle and record the voltage as MEAS3.
CALIBRATION
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