Table of Contents
Advertisement
ANTICIPATED
DIFFERENTIAL
VALUE (pF)
MULTIPLY C
SWITCH
DIVIDE G/
MULTIPLY R
SWITCH
C/L
SWITCH
CONDUCTANCE
CONTROL
G-SCALE
100 to 1000
1
1
L
■pm
10 to 100
0.1
1
C
1 to 10
0.01
10
C
!fSIS9
B
0.1 to 1
0.001
100
C
mmmB
0 to 0.1
0.0001
1000
C
-100*
*Tenth (red) subdivision on G-scale to the left of zero0
do Zero-balance the bridge as described in paragraph 3.5.
e. Set the meter switch to ZERO CENTER.
If necessary, adjust the C ZERO FINE
control for a midscale meter indication.
f. Refer to the chart in Step c, above, and set the CONDUCTANCE control to
the required position.
g. Adjust the PHASE control until the meter needle is at midscale.
h. Return the CONDUCTANCE control to zero on the G-scale.
i. If the C/L switch is at C, proceed to Step I, below.
If the C/L switch is at
L, set it to the C position.
j. Set the meter switch to ZERO LEFT and zero balance the bridge as described
in paragraph 3.5.
k. Set the meter switch to ZERO CENTER.
If necessary, adjust the C ZERO FINE
control for a midscale meter indication.
l. Connect the test specimen either to the TEST binding posts or to the REMOTE
TEST coaxial connectors, test jig, or test leads, as required.
m„ At the REMOTE STD terminals, connect a reference capacitor whose value and
accuracy are known.
n. Advance the CAPACITANCE control for an exact midscale indication on the
meter.
If the meter does not null at midscale, the value of the reference
capacitor is greater than the value of the test specimen; interchange the two
capacitors and readjust the CAPACITANCE control.
o. Read the differential value on the CAPACITANCE dial.
If the two capacitors were interchanged in Step n, above, the dial reading
indicates the negative differential value of the test specimen with respect to
the reference capacitor.
3.9.5
MEASURING CAPACITOR TEMPERATURE COEFFICIENT IN PHASE MODE.
a. Check that the initial settings on the front panel of the Model 75D are in
accordance with Table 4.
75 D
b-370
39
Advertisement
Table of Contents
