Table of Contents
Advertisement
switch (in volts).
If it is desired that a time ccnstant be introduced
into the integrating
circuit
the appropriate
shunt resistor
may be
selected by the function
switch.
Practically,
it is suggested that the capacitor be enclosed in a ground-
ed can.
The connection to the GUARD terminal may be made by a simple un-
shielded lead.
The connection to the input terminal
should be made by
means of a coaxial connection to one side of a Wee" adapter.
The cur-
rent input is made to.the
other side of the %eeu.
The following
procedure is suggested:
Depress the ZERO
CHECK
switch,
thus removing the charge from the capacitor
and shorting the input.
Zero if necessary.
Release the ZERO CHECK switch.
If the integration
is to take place over a long period of time it is suggested that the
instrument be used cx the one volt range or higher so that zero drift
and grid current will
not be factors.
CURRENT SOURCE: When measuring ohms, the instrument is designed to supply
a constant current to any device placed across its input terminals.
The
magnitude of the current is equal to the reciprocal
of the designation
on
the OHMS segment of the RANGE switch.
Therefore the instrument may be
used as a current source for calibration
of other instruments
if desired.
Depress ZERO CHECK and turn RANGE switch to OHMS. The current that is
supplied on each range is the reciprocal,of
the OHMS setting,
and is not
affected by the setting
of the MULTIPLIER switch.
However, for the cur-
,rent to be accurate, the amplifier
should be in balance.
It will
be
sufficient
to balance the amplifier
on the .l volt range of the MJLTI-
PLIER Switch.
STATIC CHARGE MEASUREMKNTS: The instrument
is zeroed and the RANGE
switch ulaced on VOLTS. The voltage sensitivity
is perhaps placed at
3 or lO*volts
full
scale.
The charged object is then brought near the
uncovered, unshielded input connector of the 600A. Depending on the dis-
tance between the charge and the instrument a voltage will
be induced on
the input terminal and can be read on the panel meter.
The instrument
zero should be checked frequently
since accumulation of charge due to the
electrometer
tube grid current will
cause a slow drift
of input voltage.
Connecting a capacitor across the input reduces the drift
due to grid
current and also the sensitivity
to charge.
An electrode
connected to
the INPUT terminal which increases the capacitance between the INPUT
terminal and the charged object will
increase the sensitivity
to charges.
I.
ZERO CENTER OPKRATION
In some applications,
such as null indication
or in measuring volt-
ages of either polarity
near zero, it may be desirable
to use the ZERO
CENTER position
on the bWl'ER-BATTERY switch.
Onthis position,
opera-
tion is just the same as for left-zero
(normal), except that for zero
input voltage or current,
the meter pointer
is at center scale.
The ZERO CENTER control
On
the rear panel is used to set the meter
pointer to zero for zero center operation.
It should require only
infrequent
attention.
3-6
0962R
Advertisement
Table of Contents
