AMETEK HPD Series User Manual
Page 57
Calibration
Current Mode Calibration
55
Current
Readback
Calibration
Procedure
1. Connect the current shunt and voltmeter to the power supply as shown in
Figure 4.2
.
2. Activate calibration mode by sending command CMODE ON or CMODE 1 to
the power supply.
3. Send command IRLO; VRLO to the power supply. Wait for the supply to settle.
Measure and record the output voltage shown on the external voltmeter. Send
IRLO again.
4. Send command IRHI; VRHI to the supply. Wait for the supply to settle. Measure
and record the output voltage shown on the external voltmeter. Send IRHI again.
5. Calculate IRLO and IRHI from the voltages taken from the external voltmeter
and the shunt resistance. I=V/R.
6. Send the command IRDAT
the current values obtained from sending the IRLO and IRHI commands to the
power supply. When the power supply is calibrated, the low to high current
readback calibration values are stored as constants.
7. Program the supply at various levels using the ISET command to confirm that
the calibration was successful and that linearity is observed. Refer to the current
readback accuracy specification in
Section 1
.
8. Turn off calibration mode by sending the command CMODE OFF or CMODE 0
to the power supply.