Keithley 616 Instruction Manual page 11

MODEL 616
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SOURCE
b. Measurements From Low Source Resistance.
use the Model 616 for voltage measurements from low
source resistances, set the RANGE switch to the 10- 1 1
AM P ERE position.
In this mode, the Model 616 input
resistance is reduced to lO ll ohms; as a result the
electrometer will be less sensitive to electrical
noise pickup and input cable vibration.
measurements can be made by following the same
procedure given 1n paragraph 3-6a.
can be used with the RANGE set at any position be­
tween 10- 11 AMPERE to 10- 1 AMPERE.
input resistance can be determined by taking the
reciprocal of the AMPERE setting.
ing error may result if the input resistance is
reduced to less than lOOx the source resistance.
c. Measurements Above 200 Volts.
can be used with accessory divider probes to measure
voltages up to 30 kilovolts. Range must be set to VOLT.
Model 6l02A Divider Probe (10:1).
1.
accessory extends the voltage measuring capability
of the Model 616 to 1000 volts.
tance is 10 10 ohms.
The divider accuracy is ±4%
to 1000 volts.
(To use the Model 6l02A an access­
ory Model 6012 Adapter is needed to mate the triax­
ial input with the UHF connector on the probe.)
2. Model 660lA Divider (100:1).
extends the voltage measuring capability of the
Model 616 to 5000 volts.
10 7 ohms.
The divider accuracy is ±0.01%.
3. Model 6l03A Divider Probe (1000:1).
accessory extends the voltage measuring capability
of the Model 616 to 30 kilovolts.
12
sistance is 10
ohms.
± 5% to 30 kilovolts.
an accessory Model 6012 Adapter is needed to mate
the triaxial input with the UHF connector on the
probe. )
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ERROR DUE TO CIRCUIT LOADING
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ERROR
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Operation As a Voltmeter in NORMAL Mode.
Figure 6.
To
Voltage
The Model 616
The Model 616
Significant load­
The Model 616
This
The input resis­
This accessory
The input resistance is
This
The input re­
The divider accuracy is
(To use the Model 6l03A
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R IN
2 x
LO
- - -
- -- -------
1 00 R
+
R IN
The Model 616 may exhibit a large amount of
zero offset or drift immediately after an
overload or a long period of storage.
addition, the offset current may exceed the
specification for a short time until the
Model 616 is sufficiently stabilized.
Although the offset current of the Model 616
is well below offset found in conventional
voltmeters, the effects of the offset current
charging the input capacitance may be noticed
when the input is open.
switch to discharge the offset charge.
The Model 616 should not be operated with cir­
cuit low floating by greater than 1000 volts
with respect to chassis ground.
616 is to be used with circuit low floating
make certain that no connection is made be­
tween the LOW and GROUND terminals on the
rear panel.
corder or other instrument to the Xl or IV
outputs when the Model 616 is floated.
d.
FAST/NORMAL Switch is set to FAST, the Model 616 is
connected in a "FEEDBACK" amplifier configuration.
In this configuration,
connections. To measure voltage,
between input HI and GUARD.
plish this connection is to connect the link (on the
rear panel) between "GUARD" (blue tenninal) and
"GROUND" (green terminal).
cable for input connections with the input voltage
applied between the "red" clip lead and the "green!!
clip lead.
In this special voltage connection, the LO
input (black clip lead) is not used since
the voltage amplifier configuration has been
changed.
OPERATING INSTRUCTIONS
Xl OU
AMPLIFIER
n
4
1 0 1
- -
- -
ELECTROMETER
NOTE
Use the ZERO CHECK
CAUTION
If the Model
Do not connect a grounded re­
the Model 616 requires special
connect the source
An
easy way to accom­
Then use the triaxial
NOTE
In
When the
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