Calibration and Troubleshooting 
 
7-6  M370430-01  Rev B 
Calibrating the Output Voltage 
Gain calibration of the power supply has the greatest effect on the 
accuracy in the high voltage range. Offset calibration has the greatest 
affect on accuracy of the power supply at low voltages. The same 
calibration command is used for the gain and offset calibrations. The 
type of calibration is determined internally by the instrument depending 
on if the set point is above 10% of the maximum output voltage value or 
not. If it is above 10% of the maximum voltage, the calibration is a gain 
calibration; if is below 10%, it is an offset calibration. 
Gain Calibration 
To perform gain calibration: 
1.  Disconnect the power supply from the load. 
2.  Connect the output terminals to a precision voltmeter. 
3.  Turn both the power supply and the voltmeter to On. 
4.  Set the current set point to maximum. Set the supply output to 
90% of the nominal voltage level. 
5.  Turn on the output power. 
6.  Read the voltage value on voltmeter display. 
7.  Type the SCPI command with voltage value as parameter 
“data”. 
For example, type :CAL:OUTP 138.3 if you had an XG (or XTR) 
150-5.6 calibrating with the voltage set point set to 135 V and the 
voltmeter was reading 138.3 volts. 
Offset Calibration 
To perform offset calibration: 
1.  After performing gain calibration, set the programmed 
voltage 10% from nominal. 
2.  Read the voltage value on the voltmeter display. 
3.  Type the SCPI command with voltage value as parameter 
“data”. 
For example, you would type : CAL: OUT P1 2 . 3 if you had an 
XG (or XTR) 150-5.6 calibration with the voltage set point set to 
10V and the voltmeter was reading 12.3 volts.