Keithley 6517 Service Manual page 26

2GΩ-200GΩ range verification
1. Connect the nominal 1GΩ characterized resistor from
the Model 5156 Calibration Standard to the Model
6517A. (See Figure 1-6.)
2. Select the ohms function.
3. Place the voltage source in operate.
4. Select the 2GΩ range on the Model 6517A.
5. Make sure that zero check is disabled, and allow the
reading to settle.
6. Verify that the displayed reading is within the calculated
reading limits listed in Table 1-9.
7. Repeat steps 4 through 6 for the 20GΩ and 200GΩ
ranges.
8. Turn off the voltage source, then disconnect the calibra-
tion standard from the Model 6517A.
2TΩ-200TΩ range verification
1. Connect the nominal 1TΩ characterized resistor to the
Model 6517A. (See Figure 1-7.)
Standard resistors must be characterized
to an uncertainty at least four times better
Model 5156 Electrometer Calibration Standard
100GΩ
1nF
100nF
Note: Be sure shield and
Chassis are linked.
Figure 1-6
Connections for ohms verification (2G Ω –200G Ω ranges)
NOTE
10GΩ
OUTPUT
1GΩ
!
100MΩ
Connect to
Center Conductor
Triax Cable
than the equivalent Model 6517A accu-
racy specifications. These resistors must
be mounted in specially shielded test fix-
tures to minimize noise. (See Figure 1-8
for details on test fixture construction.)
WARNING
Hazardous voltage (400V) will be used
in the following steps. Do not touch con-
necting cables or test leads while the
voltage source is in operate.
2. Select the 2TΩ range on the Model 6517A.
3. Place the voltage source in operate.
4. Make sure that zero check is disabled, and allow the
reading to settle.
5. Verify that the displayed reading is within the calculated
limits listed in Table 1-9.
6. Repeat steps 2 through 5 for the 20TΩ and 200TΩ
ranges.
7. Turn off the voltage source, then disconnect the standard
resistor from the Model 6517A.
WARNING:
WARNING:
NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY. NO INTERNAL OPERATOR SERVICABLE PARTS,SERVICE BY QUALIFIED PERSONNEL ONLY.
1010V
PEAK
LO
PREAMP OUT COMMON 2V ANALOG
! V SOURCE
250 PEAK OUTPUT
INPUT
750V
250V PEAK
PEAK
TEMP HUMIDITY
EXT TRIG MTR COMP
TYPE K
IN OUT
RS232
DIGITAL
I/O
OPTION SLOT
!
INTERLOCK
CAUTION: CAUTION:
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING. FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,REPLACE FUSE WITH SAME TYPE AND RATING.
Model 6517 Electrometer
Performance Verification
Voltage Source HI
HI
MADE
SELECTED
IN
LINE VOLTAGE
U.S.A.
90-110V 180-220V
105-125V 210-250V
LINE RATING LINE FUSE
50-60HZ SLOWBLOW
50VA MAX 1/2A 90-125V
AC ONLY
1/4A 180-250V
IEEE-488
(CHANGE IEEE ADDRESS
WITH FRONT PANEL MENU)
TRIG LINK
1-13