Table of Contents
Advertisement
MODELS 610B,
610BR ELECTROMETERS
OPERATION
c.
The value
of the unknown
capacitance
is
the
stored
charge
divided
by the
initial
voltage:
c (farads)
=
Q
(='ulo~S~
v (volts)
Z-14.
APPLICATION
NOTES.
The versatility
of the Model
610B is
such
that
it
is almost
a complete
dc laboratory
in
itself.
Some particular
applications
follow;
the
purpose
of these
is
to suggest
uses and techniques
to increase
the
usefulness
of the Model
610B.
a.
current
1nceerator.
The Model
6lOB works
as an integrator
for
time-varying
currents,
Figure
10 shows
the
circuit.
Set the Range Switch
to COULOMBS.
Use
the unity-gain
output.
Output
voltage,
V,ut,
is
=+
/
T
Vout
i dt
0
where
C is
the
coulomb
range
setting
in
farads
610B
610B
Xl Xl
b b
GUARD
GUARD
L L
FIGURE 10.
Current
Integrator.
The diagram
shows
the Model
610B acting
as a
current
integrator.
A square
wave from
a current
source,
I,,
is applied
to the
Model
610B input.
Using
the COULOMBS ranges,
the
output
through
the
unity-gain
terminals
is
shown.
b.
Potentiometric
Voltage
Measurement%.
The high
input
impedance,
l-millivolt
sensitiv~ity
and low zero
drift
make the Model
6108 useful
as a potentiometer.
The circuit
shown in Figure
11 is useful
when no loading
of
the
source
voltage,
on or off
null,
can be tolerated.
Make the measurements
with
the
center
zero
scale,
following
the
procedures
in paragraph
2-5.
When the Model
610B is
at null
-
no meter
deflection
-
the
voltage
from
the known source
equals
the unknown
voltane.
Voltage
Supply
Voltage
Supply
+
-
+
-
,
FIGURE 11.
Potentiomecric
Voltage
Measurements.
An accurate
voltage
supply
is
used to buck
out
the
potential
from
the unknown
source,
V,.
The Node1 610B on
the voltage
ranges
and center-zero
scales
acts
as a null
detector.
1264~
19
Advertisement
Table of Contents
