Service manual

CALIBRATION TW SERIES
3-30
Query the TW’s watts using the GPIB string below, and record this value as MEAS2.
MEAS{1,2,3}:POW?
Turn the TW’s output off via the GPIB:
OUTP OFF
Calculate the gain and offset values for updating the TW:
GAIN = (RDGN2 – RDGN1)/(MEAS2 – MEAS1)
OFFSET = RDGN2 – GAIN * MEAS2
Update the TW’s gain and offset calibration values with the following GPIB strings:
CAL{1,2,3}:MEAS:LOC:LOR:WATT:GAIN GAIN
CAL{1,2,3}:MEAS:LOC:LOR:WATT:OFFSET GAIN
3.21 REMOTE LOW RANGE WATTS CALIBRATION
Connect the 12 ohm resistor to the output of the TW through the power analyzer. Set
up the power analyzer to measure watts.
Set up the TW to AC coupling, low range, local sense, 13 ampere current limit, output
relay closed and 54 volts with the following GPIB programming strings:
OUTP:COUP AC
SOUR:VOLT:RANGE LOW
SOUR:SENSE REMOTE
SOUR{1,2,3}:CURR 13.00
OUTPUT ON
SOUR{1,2,3}:VOLT 54
Wait until the power analyzer has stabilized and record the watts reading as RDNG1.
Query the TW’s watts using the GPIB string below, and record this value as MEAS1.
MEAS{1,2,3}:POW?
Program the TW to 134 volts AC using the string below:
SOUR{1,2,3}:VOLT 134
Wait until the power analyzer has stabilized and record the watts reading as RDNG2.
Query the TW’s watts using the GPIB string below, and record this value as MEAS2.
MEAS{1,2,3}:POW?