Keithley 6512, Instruction Manual

Page: 95 / 156

Performance Verification
5-5
* The 200mV, 2V, and 20V ranges allowable readings include Model 263 error. The 200V range reading is based solely on Model 6512 accuracy specifica-
tions.
5.5.5 Ohms verification
Connect the Model 6512 to the Model 263, as shown in Figure 5-3, and perform ohms verification as follows:
NOTE
Charge and current verification must be performed before resistance verification.
1. Set the Model 6512 to the 2k
Ω
range.
2. Zero correct the Model 6512 by enabling zero check and zero correct in that order.
3. Set the Model 263 to the 1k
Ω
range, and while in OPERATE, press ZERO to source zero ohms to the Model 6512.
4. Release zero check on the Model 6512, and allow the reading to settle.
5. On the Model 6512, press SUPPRESS to cancel offset and test lead resistance.
6. On the Model 263, source the 1k
Ω
resistor to the Model 6512. The actual value of the output resistance is displayed on the
Model 263.
7. Record the Model 263 reading in Table 5-3.
8. Calculate the Model 6512 reading limit using the formula in the table.
9. Verify that the reading on the Model 6512 is within the limits calculated in step 8.
10. Referring to Table 5-3, repeat the basic procedure in steps 3 through 9 for the 20k
Ω
range.
Table 5-2
Limits for volts verification
6512
range 263
output Allowable reading
(1 year, 18°-28°C)
200mV
2V
20V
200V 190.000mV
1.90000V
19.0000V
190.000V 189.91 to 190.09mV
1.8993 to 1.9007V
18.993 to 19.007V
189.86 to 190.14V
Figure 5-2
Connections for volts verification
2-SLOT
TRIAX
CABLE
EXT INPUT
CHASSIS
DC CALIBRATOR
LO
HI
DUAL BANANA CABLE
COMMON
MODEL 263 MODEL 6512
6171 3-SLOT MALE TO
2-LUG FEMALE TRIAX
ADAPTER
EXTERNAL CALIBRATOR SOURCE
V,
Ω
GUARD
OFF