TM 11-6625-539-14-4
7-19. Ohms Measurement Tests
b. Test Connections and Conditions. As indi-
cated below.
a. Test Equipment and Materials.
c. Procedure.
(1) Resistor, Decade ZM-16/U.
(2) Multimeter AN/USM-223.
('ontrol settings
Step
Performance
Test procedures
No.
Test
Equipment
equipment
under test
1
N/A
POLARITY switch:
a. Meter deflects to near full
a. Check meter deflection.
scale.
E-B.
FUNCTION switch:
b. Meter shows exact full-scale
b. Adjust meter for full-scale
deflection.
OHMS:
deflection.
c. Meter can be adjusted to
R A N G E switch: X
c. Short across EB jacks and
0.1.
check zero deflection of me-
zero.
ter.
ICES
ZERO/OHMS
d. Opne EB contacts result in
d. Repeat a through c above un-
exact full-scale deflection.
ADJUST controls.
til full scale deflection and
When shorted, meter reads
METER ZERO con-
zero deflection are achieved.
exact zero.
trol.
Meter must read 300 ohms 5
C o n n e c t decade box to
E-B
Same.
2
Set decade box to 30
percent on OHMS scale.
jacks.
ohms.
Meter must read 1k ohms 5
C o n n e c t decade box to
E-B
Same.
3
Set decade box to 100
percent on OHMS scale.
jacks.
ohms.
Meter must read 3k ohms 5
C o n n e c t decade box to
E-B
4
Set decade box to 300
Same.
percent on OHMS scale.
jacks.
ohms.
Meter must read 300, 1k, and 3k
Repeat steps 2 through 4
con-
5
Set decade box to 30,
Same except PO-
ohms on OHMS scale with
LARITY switch:
necting decade box to
CB
100, and 300 ohms
successive tests. All readings
C-B.
jacks.
successively,
must be 5 percent of decade
box setting.
Meter must read 300, 1k, and 3k
Repeat steps 2 through 4 con-
6
Set decade box to 30,
Same except PO-
ohms on OHMS scale with
necting decade box to EC
100, and 300 ohms
LARITY switch:
successive tests. All readings
jacks.
successively.
E-C.
must be within 5 percent of
decade box setting.
Open E-B terminals cause full-
Repeat
step 1 to adjust full-
POLARITY switch:
`7
N/A
scale deflection. When EB
C-B.
scale
deflection with CB
terminals are shorted, meter
R A N G E switch: X
open
and zero deflection
is exactly zeroed.
1.0.
when
shorted.
F U N C T I O N switch:
OHMS.
Meter must read 300, 1k, and 3k
Repeat steps 2 through 6 to
Same.
8
S e t decade box to
check out resistive loading of
ohms on OHMS scale with
300, 1K, and 3K
successive tests. All readings
C-B at each of the selected
ohms successively.
must be within 5 percent of
decade box settings.
Open. terminals cause full scale
Repeat
step 1 to adjust full
POLARITY switch:
N/A
9
deflection. When E-B termi-
E-C.
scale
deflection with EC
nals are shorted, meter is ex-
FUNCTION switch:
open
and zero deflection
actly zeroed.
when
shorted.
OHMS
R A N G E switch: X
10.
Meter must read 300 and 1k on
Repeat steps 2 through 6 to
Same.
10
Set decade 3K and
the OHMS scale with succes-
check out resistive loading of
10K ohms succes-
s i v e tests. Both readings
E-C at each of the selected
sively.
must be within 5 percent of
decade box setting.
7-12
