Out-Of-Circuit Transistor Resistance; Resistance Measurements - HP 4328A Operating And Service Manual

' I
I
' I
Section V
Table 5-6 and 5-7
Table 5-5. Out-of-Circuit Transistor
Resistance Measurements
Connect Ohmmeter
Measure
Transistor
Resistance
Type
Pos,
Neg.
(ohms)
lead to lead to
emttter base* 200-250
Small
Signal
emttter collector lOK-lOOK
PNP
Germa-
emitter
base*
30-50
nium
Power
emitter collector
several
hundred
emitter base* lOK-lOOK
PNP Small
Silicon Signal
very higll
emitter collector (might
read open)
base
emitter 1K-3K
Small
very high
Signal
collector emitter (might
NPN
read open)
Silicon
base emitter 200-1000
Power
high, often
collector emitter
greater
than 1M
* To test for transistor action, add collector-
5-6
base short.
Measured resistance should
decrease,
CAUTION
Most ohmmeters can supply enough current
or voltage to damage a transistor. Before
usmg an ohmmeter to measure transistor
forward or reverse resistance, check 1ts
open-circuit voltage and short-ctrcuit cur-
rentoutputON THE RANGE TO BE USED.
Open-circuit voltage must not exceed 1. 5
volts and short-circuit current must be
less than 3ma. See Table 5-6 for safe
resistance ranges for some common ohm-
meters.,
Model 4328A
Table 5-6. Safe Ohmmeter Range for
Transistor Resistance
Measurement~
Open Open
Ohm- Safe Ckt Ckt
meter Range(s) Voltage Current Color Polarity
RxlK
1.
ov
lmA
RxlOK l.OV lOOJ.LA
HP412A
Rx lOOK l.OV lOJ.LA
Red +
HP427A
Black
-
RxlM
1.
ov
lilA
RxlOM
1.
ov
0. lilA
RxlK 1.3V 0.57mA
RxlOK
1.3V 57J.LA
+
HP410C RxlOOK
1. 3V 5.7J.LA
Red
Black
-
RxlM 1. 3V
o.
5J.LA
RxlOM
1. 3V 0. 05J.LA
RxlOO l.lV l.lmA
RxlK l.lV llOJ.LA
HP410B RxlOK
l.lV
llJ.LA
Black
+
Rx lOOK
l.lV 1. lilA
Red
-
RxlM l.lV 0. 11/lA
Simpson RxlOO
1.5V lmA Red
+
260 Black
-
Simpson RxlK
1.5V 0.82mA Black +
269
Red
-
Triplett RxlOO 1.5V 3.25mA
630 RxlK 1.5V 325p.A
Varies with
Serial
Triplett Rx 10 1.5V
750p.A
Number
310 RxlOO
1.5V 75J.LA
1,11 1
1,"
I
(
, ' ' ,,,:l
I
~ti
C'-"'"1
j,
t