Tektronix Type 130, Instruction Manual

Page: 12 / 53

Operating Instructions — Type 130
2-4
AA
Inductance with Series Resistance
Correction,
μ
h
Series
Resistance
At 0
μ
h At 100
μ
H At 300
μ
H
0 Ω
0.00 0.00 0.00
1 Ω –0.06 –0.04
+0.03
2 Ω –0.12 –0.08
+0.06
4 Ω –0.18 –0.12
+0.18
6 Ω –0.19 –0.11
+0.35
8 Ω –0.15 –0.03
+0.55
10 Ω –0.06
+0.10 +0.80
15 Ω
+0.37 +0.60 +1.66
20 Ω
+1.11 +1.40 +2.80
30 Ω
+3.60 +3.86 +6.08
40 Ω
+7.40 +7.90 +10.80
Precautions
Reactors much greater than 300
μμ
f or
μ
h can cause er-
roneous readings. The counter circuit may be unable to
follow the large difference in frequency that results, but
still develop dc current that will put the meter on scale.
The meter needle will flutter and be unstable and the
COARSE ZERO adjustment will give erratic results to warn
you to question the reading. Be sceptical of any reading
you get if it is at all unstable.
Be sure you raise the frequency of the oscillator when
you suppress zero. You can be sure of this if turning ZERO
control clockwise sends the needle toward zero, and the
white index on the knob is up.
Capacitance with Parallel Resistance
Correction,
μμ
f
Shunt
Resistance
At 0
μμ
f At 100
μμ
f At 300
μμf
4 meg
–0.02 –0.01
+0.01
2 meg
–0.04 –0.02
+0.02
1 meg
–0.09 –0.04
+0.03
.5 meg
–0.13 –0.08
+0.10
300 k
–0.18 –0.06
+0.22
200 k
–0.20 –0.01
+0.39
150 k
–0.18
+0.08 +0.56
100 k
–0.08
+0.36 +1.14
80 k +0.09 +0.60 +1.64
60 k +0.06 +1.45 +2.70
50 k +1.15 +2.15 +3.68
40 k +2.20 +3.35 +5.40
30 k +4.70 +6.05 +9.00
Do not suppress zero for inductance measurements, and
do not compensate for large residual inductance with the
ZERO adjustment. Additional inductance in the oscillator
circuit changes the amount of total capacitance required
to cause the meter to read zero, and therefore affects the
scale accuracy. If there is unavoidable residual inductance
in a measurement, measure the residual and subtract it
from the total inductance you measure. Correction of 10
μ
h
of residual inductance by the ZERO controls will cause
noticeable
error in the inductance reading.