Constant Resistance (CR) verification
Resistance programming and readback accuracy
Test category = performance
This test verifies that the resistance programming is within specification. The programmed resistance values are
checked by recording the voltage across the current monitor resistor and the input voltage (voltage at the modules
+ and – sense terminals), then calculating the resistance as follows;
Resistance = Input Voltage / (voltage across current monitor / monitor resistor value)
The Resistance value must then be converted to Siemens by inverting the value: S = 1/R
1.
Turn off the electronic load.
2.
Connect a DMM, current shunt, and an external power supply across the input terminals (see
).
Connect the DMM directly across the current shunt. Connect "DMM 2" across the sense terminals.
3.
Turn on the electronic load.
Ultra-High range (EL34143A and EL34243A only)
4.
Program the load settings as described in the test record form for “Resistance Programming - Ultra-High
range, Minimum resistance”. Turn on the power supply and program it to the power supply settings described
in the test record form.
5.
Turn the load input on. The load status should be “CR”.
6.
Divide the voltage drop (DMM reading) across the current shunt by the shunt resistance to convert to amps and
record this value (Iin).
7.
Calculate the resistance value as follows: R = Vin/Iin. Vin is the voltage measured by the second DMM. Convert
the input resistance (R) to Siemens by inverting the value: S = 1/R. The value in Siemens should not exceed value
listed in the test record under “Resistance Programming - Ultra-High range, Minimum resistance”.
8.
Program the load settings as described in the test record form under “Resistance Programming - Ultra-High
range, Maximum resistance”. Program the power supply to the power supply settings described in the test
record form.
9.
Divide the voltage drop (DMM reading) across the current shunt by the shunt resistance to convert to amps and
record this value (Iin).
10.
Calculate the resistance value as follows: R = Vin/Iin. Vin is the voltage measured by the second DMM. Convert
the input resistance (R) to Siemens by inverting the value: S = 1/R. The value in Siemens should not exceed value
listed in the test record under “Resistance Programming - Ultra-High range, Maximum resistance”.
High range
11.
Program the load settings as described in the test record form for “Resistance Programming - High range,
Minimum resistance”. Turn on the power supply and program it to the power supply settings described in the
test record form.
12.
Turn the load input on. The load status should be “CR”.
Keysight EL30000 Series Service Guide
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