Keithley 6514, Instruction Manual

Page: 63 / 334

3-6 Volts and Ohms Measurements
RS232 DIGITAL I/O
PREAMP OUT
250V PK
2V ANALOG
OUTPUT
COMMON CHASSIS
120
FUSE LINE
630mA
LINE RATING
50, 60Hz
60 VA MAX
T
(SB)
100 VAC
120 VAC
315mAT
(SB)
220 VAC
240 VAC
INPUT 250V PK
IEEE-488
(CHANGE IEEE ADDRESS
WITH FRONT PANEL MENU)
TRIGGER LINK
!
!
MADE IN
U.S.A.
V, GUARD
(PROGRAMMABLE)
OFF ON
GUARD
(FOLLOWS
INPUT)
(INTERNAL)
INPUT PREAMP
10K
PREAMP
OUT
2V ANALOG
OUTPUT
COM
Red (HI)
LO
237-ALG-2
Cable
Metal Guard Plate
6514 Rear Panel
GRD Enabled
Black
(GRD)
Metal Safety Shield
Safety
Earth
Ground
Green
(Chassis)
DUT
Guarded connections
— Connections for guarded volts and ohms measurements are shown
in Figure 3-3. The driven guard (GRD) must be enabled for these measurements.
WARNING With an open input, up to 250V peak may be present on the guard terminals
while in Volts or Ohms. To prevent this, make sure zero check is enabled
whenever the input is open.
Step 6 Disable zero check and take a reading from the display
V-Drop and I-Source for ohms
Model 6514 performs ohms measurement by sourcing a known test current through the DUT
and then measuring the voltage drop across it. The resistance reading is then calculated
(R = V/I) and displayed.
Figure 3-3
Connections for
guarded volts and
ohms