iET PRS-330 series, Operation Manual, Page: 52 / 67

MAINTENANCE
PRS-330 Series
40
Figure 8-3 Password entry screen
Figure 8-4 Entry of IET as password
Once the password IET has been input via touch
screen press the ENTER key. This will open the
Calibration screen as shown in Figure 8-5.
Figure 8-5 Resistor 1 Calibration Screen
The process is to measure the resistance with
a DMM using a 4 terminal Kelvin connection,
making sure the shorting links are not on the
binding post.
IET Labs uses the Fluke 8508A, set to 7 ½ digits
of resolution, during the adjustment process to
ensure the PRS-330 meets speci
fi cations.
IET Labs offers the PRS-DMM software which
works with the PRS-330 and Fluke 8508A or
Keysight 3458A to automate this adjustment
process. See Chapter 9.
Once the resistance is measured the resistance
value can be manually entered in ohms using
the keypad.
Once the resistance has been entered the NEXT
key can be pressed to move to the next resistor
value R2. The PREV key can be used to go back
to the previous resistance value if required. There
are 43 resistors which require calibration.
At anytime during the process the CNCL key
can be pressed to cancel the calibration process.
Cancelling the calibration process will not save
any calibration data taken and the previous
calibration data is used.
Pressing the EXIT key will save the current
calibration data into memory. You will be
prompted to enter the calibration date. and then
the data is saved into memory. This data can be
reviewed in the Calibration History menu.
8.1.7 Calibration History
The Calibration History menu is in the Calibration
menu. This allows the use to view the resistance
and date the adjustment procedure as perform in
Section 8.1.4.
This information can be used to look at the drift
of each of the 43 internal resistors. This data can