Service manual

CALIBRATION TW SERIES
3-22
Calculate the measurement system frequency compensation values:
VALUE1 = RDGN1 / MEAS1
VALUE2 = RDGN2 / MEAS2
VALUE3 = RDGN3 / MEAS3
VALUE4 = RDGN4 / MEAS4
VALUE5 = RDGN5 / MEAS5
Update the TW’s calibration data with the following GPIB command:
CAL{1,2,3}:MEAS:REM:HIR:VOLT:FREQCAL VALUE1 VALUE2 VALUE3 VALUE4 VALUE5
3.15 EXTERNAL PHASE REFERENCE CALIBRATION
Connect the counter timer channel 1 to the TW’s A phase through a 10:1 resistor
divider. Connect the counter timer channel 2 to the TW’s clock/lock/sync BNC. Set the
counter time up to measure phase angle.
Set up the TW for the external refout, low range, local sense, 40 Hz, 120 V and close
the output relay by sending the following GPIB commands:
SYST:EXT:CLOCK REFOUT
SOUR:VOLT:RANGE LOW
SOUR:SENSE LOCAL
SOUR:FREQ 40.0
SOUR:VOLT 120.00
OUTPUT ON
Wait for the phase angle measurement to stabilize on the counter timer. Record the
phase angle as RDGN1.
Set the TW frequency to 80 Hz:
SOUR:FREQ 80.0
Wait for the phase angle measurement to stabilize on the counter timer. Record the
phase angle as RDGN2.
Set the TW frequency to 160 Hz:
SOUR:FREQ 160.0
Wait for the phase angle measurement to stabilize on the counter timer. Record the
phase angle as RDGN3.
Set the TW frequency to 160 Hz:
SOUR:FREQ 160.0