Verifying Resistance - Keithley SourceMeter 2790 Reference Manual

16-14

Verifying resistance

Check the resistance function by connecting accurate resistance values to the Model 2790
and verifying that its resistance readings are within the specified limits.
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Follow these steps to verify resistance accuracy:
1.
Figure 16-5
Connections for Model 2790 resistance verification (100
Model 2790
Model 2790 SourceMeter Switch System
MATH O U T P U T RATIO CH AVG CONT OCOMP PERIOD SENSOR
Ω2 Ω4
SHIFT DCV ACV DCI ACI FREQ
HOLD MONITOR
DELAY LIMITS ON/OFF TYPE CH-OFF
LOCAL
EX TRIG TRIG STORE RECALL FILTER REL
POWER
SAVE SETUP CONFIG HALT TEST LSYNC GPIB
OPEN CLOSE STEP SCAN DIGITS RATE EXIT
SENSE LO
2.
3.
4.
5.
6.
7.
Do not apply more than 1000V peak between front terminals INPUT
HI and LO or more than 350V peak between SENSE HI and LO, or
instrument damage could occur.
Using shielded, Teflon-insulated or equivalent cables in a 4-wire configuration,
connect the Model 2790 INPUT and SENSE jacks to the calibrator as shown in
Figure 16-5. Be sure the INPUTS switch is in the FRONT position.
SENSE
INPUT HI
HI
SENSE
INPUT
Ω 4 WIRE
HI
350V 1000V
!
PEAK PEAK
LO
500V
PEAK
INPUTS
TEMP
RANGE F R
F
F
CARD
AUTO
FRONT/REAR
3A 250V
AMPS
RANGE
RS-232
ENTER
INPUT LO
Set the calibrator for 4-wire resistance with external sense on.
Select the Model 2790 4-wire resistance function by pressing the Ω4 key, then
choose the SLOW integration rate with the RATE key.
Set the Model 2790 for the 100Ω range and make sure the FILTER is on. Enable
OCOMP (offset-compensated ohms) by pressing SHIFT then OCOMP. (Use
OCOMP for 100Ω range verification.)
Recalculate reading limits based on actual calibrator resistance values.
Source the nominal full-scale resistance values for the 100Ω-10MΩ ranges summa-
rized in Table 16-6 and verify that the readings are within calculated limits.
Connect the Model 2790 INPUT and SENSE jacks to the calibrator as shown in
Figure 16-6.
Model 2790 SourceMeter
Ω Ω
to 10M
SENSE HI
OUTPUT
HI
OUTPUT
LO
SENSE LO
NOTE Use shielded low-thermal cables to
minimize noise. Enable calibrator
external sense.
®
Switch System Reference Manual
ranges)
Resistance Calibrator