7526A
Calibration Manual
28
Enter
5
on the PC. The calibration procedure for current output is similar to voltage
output except there is only one range and the voltage is measured across a 10
Ω
shunt
resistor instead of a direct current measurement. Readings from the DMM must be
converted to mA (multiplied by 100) before they can be entered on the PC.
Steps 6 and 7: Hi Ohms Source and Low Ohms Source Adjustment
When the 5
Ω
- 4000
Ω
output range (high ohms source) is calibrated, the Product
outputs two calibration points. After the output becomes stable, the values are entered at
the PC. See Table 3 for the test equipment used for this procedure. See Figure 14 for
connections.
CURRENT
OUTPUT
HI
VOLTS
mA
RTD/
OUTPUT
HI
LO
HI
LO
LO
TC
SENSE
INPUT/OUTPUT
4W RTD/
INPUT
20 V PK
MAX
100 V MAX
100 mA MAX
20 V PK
MAX
20 V PK
MAX
PRECISION PROCESS CALIBRATOR
7526A
7526A
8508A
gxm021.eps
Figure 14. Hi Ohms Source and Low Ohms Source Adjustment Connections
It is important that the sense leads be on the bottom of the stack on the Product ohms
source jacks.
1.
Set the DMM to measure 4-wire ohms.
2.
The calibration of the 5
Ω
- 4000
Ω
output range (high ohms source) is similar to the
voltage source calibration. The Product outputs two calibration points. After the
output becomes stable, enter the values on the PC.
It is recommended to lock the DMM in the proper range (first range greater than
4000
Ω
). The maximum excitation current of the DMM is 1 mA.
3.
Enter the ohms shown on the DMM at the PC. The Product sources the maximum
value.
4.
Enter the ohms shown on the DMM at the PC. After the value has been entered for
the second calibration point you will return to the main calibration menu.
The calibration of the 5
Ω
- 400
Ω
output range (low ohms source) is similar. The
maximum excitation current of the DMM is 3 mA.
Summary of Contents for 7526A
Page 6: ...7526A Calibration Manual iv ...
