Section B-Performance Verification - Keithley 595 Instruction Manual

PERFORMANCE VERIFICATION
NOTE
Do
not touch the body of the resistor to avoid con-
tamination which could give erroneous results.
9. Calculate the actual calibrator voltage by multiplying the
measured resistor value by the CalibratiOn current for
that range. For example, if the adual resistance is 99MQ,
the required calibrator voltage is V=(99 x 106)
(19 x .JP) = 1.881V. Write the calculated value &I Table
6-2.
10. Set the calibrator voltage to the exact value obtained in
step 9.
11. Place the instrument on the 20nA range~and enable
ZEROS CHECK. Verify that the display shows O.oOOnA
+1 count. lf not, perform Correct.
12. Mount the lOOM0 resistor in the shielded fixture (con-
struction is covered in Figure 6-1) and connect the fii-
@me tom the instrument, as shown in Figure 6-3.
13. Disable ZERO CHECK and verify that the reading is
within the limits given in Table 6-2. Enable ZERO
CHECK.
14. Repeat steps 8 through I3 for the 2OpA - 2nA ranges.
For each range, measure the actual resistor value and
calculate the caBration voltage using that value along
with the required callkation cm-rent.
RESISTOR
+
SHIELDED FIXTURE
(SEE
FIGURE 6-I)
w
DC CALIBRATOR
LB01
ABLE
t
SHORTING
LINKS
CONNECTED
SHORTING LINK
MODEL 595
DISCONNECTED
Figure 6-3. Setup for Current Verification (2OpA to 20nA Ranges)
6-5