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Model 4277A
SECTION III
3-65.
MEASUREMENT ACCURACY
3-66. The measurement reference plane for the
accuracies
specified
in
Section
I
is
the
UNKNOWN
terminals.
The
measurement
accuracy of the 4277A is guaranteed at the
UNKNOWN terminals.
The conditions under
which accuracy is specified are described in
Table 1-1. An example of the how to calculate
measurement accuracy is shown in Figure 3-19.
3-67. GENERAL COMPONENT MEASUREMENT
3-68. The
procedures
for
measuring
general
components—inductors,
capacitors,
resistors—
are given in Figure 3-20.
Almost any discrete
component,
except
for
those
having special
shapes or dimensions, can be measured with this
setup. Special components may be measured by
using test leads 16048A, 16048B, 16034B, etc., or
by using specially designed user-built fixtures
instead of the 16047A Test Fixture.
3-69. SEMICONDUCTOR DEVICE
MEASUREMENT
3-70. As an example of a typical semiconductor
measurement, the procedures for measuring the
base-collector junction capacitance (C ob) of an
NPN transistor are given in Figure 3-21.
[Examples
of
Calculating
C,
D,
and
Q
Measurement Accuracies]
[Examples
of
Calculating
C
and
ESR/G
Measurement Accuracies]
Front Panel Settings:
Front Panel Settings:
Test Frequency: IMHz
LC i Z i
RANGE: lOOpF
TEST SIG LEVEL: HIGH
MEAS SPEED: MED
Test Frequency: lOkllz
LC ! Z i
RANGE: 1 yF
TEST SIG LEVEL: HIGH
MEAS SPEED: MED
Measured Values:
Measured Values:
C: 148.97pF
D: .0005
Q: OF (Assume a value of Qm)
C: .905mF
ESR: .3Q
G: 1.0 mS
Accuracies (Refer to Table 1-1):
Accuracies:
C;
±.l96 of reading + 5 counts
148.97pFx (.1/100)+ .05pF
= (±) 0.199pF
D:
±.396 of reading + .
0005
/a + .0006 + 5
counts
.0005
X
(.3/100) + .0005/1.4897 + .0006
+ .0005
= (±).00144
Q:
Qm
X
(.00144/.0005) + .1
= ± (Qm
X
2.88 + .1)
C:
(.3 + .5a)96 of reading + 3 counts
.905mF
X
(.3 + .5
X
.905)/100 + .003
= (±) O.OlSOpF
ESR: .296 of reading + 30amfi + 20mf2 +
5 counts
X
.2/100 + 30
X
.905mQ + 20mQ
+ .5Q
= (±) 550mfi
G:
ImS
X
(550/300)
^ (±) 1.83mS
Note
In this case, Q accuracy (2.88 times Q )
has no meaning, because Q
is overflow
(OF).
Figure 3-19. How to Calculate Measurement Accuracies.
3-45
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