TM 1-1500-204-23-4
1
Remove gauge to be shop tested.
2
Obtain
mercury
centigrade
thermometer NSN 6685-00-851-4577.
3
Fill container with fresh water and
allow water to stabilize at room temperature. (Allow to
sit overnight, if possible.
4
Remove sun shields and suspend
gauge in such a way that the stems are vertical and are
immersed two to two and a half inches into the water.
Simultaneously, suspend the mercury thermometer in
the water to an equal depth.
5
Record the mercury thermometer
and gauge temperature after five minutes. Allow an
additional five minutes to pass and record temperatures
again. Repeat until temperatures stabilize.
6
Fill a container with ice cubes or
crushed ice and water.
7
Place the gauge with stems vertical
into the ice-water approximately two to two and a half
inches.
Simultaneously,
immerse
the
mercury
thermometer to the same depth.
8
Record the mercury thermometer
and gauge temperature after five minutes. Allow an
additional five minutes to pass and record temperatures
again. Repeat until temperatures stabilize.
(b)
Replacement criteria. Gauges must
agree with the mercury thermometer within two degrees
at both test points. Failure to meet either test point
within two degrees is cause for rejection.
(3)
Temperature Conversion. To convert
Fahrenheit to centigrade or centigrade to Fahrenheit,
use table 4-13 or the following conversion formulas.
C = (5/9) x (F-32)
F = [(9/5) x C] + 32
Example: change 86 °F
Example: change 40C
to Centigrade
to Fahrenheit
C = (5/9) x (F-32)
F = [(9/5 x C] + 32
C = .5556 x (86-32)
F = (1. 8 x 40) + 32
C = .5556 x (54)
F = 72 + 32
C = 300
F = 104
n.
Deleted.
o.
Magnetic Compass. The magnetic compass, as
shown in figure 4-19, consists of liquid-filled bowl
containing a pivoted float element to which one or more
bar magnets, called needles, are fastened. The liquid
dampens the oscillations of the float and decreases the
friction of the pivot. A diaphragm and a vent provide for
expansion and contraction of the liquid as altitude and
temperature change. Principles of operation, compass
errors, compass compensation, and replacement criteria
are described by the following paragraphs.
Table 4-13. Fahrenheit-Centigrade Conversion Chart
°C
°F
°C
°F
°C
°F
°C
°F
°C
°F
-50
-58
-20
-4.0
10
50.0
40
104.0
70
158.0
-48
-54.4
-18
-0.4
12
53.6
42
107.6
72
161.6
-46
-50.8
-16
3.2
14
57.2
44
111.2
74
165.2
-44
-47.2
-14
6.8
16
60.8
46
114.8
76
168.8
-42
-43.6
-12
10.4
18
64.4
48
118.4
78
172.4
-40
-40.0
-10
14.0
20
68.0
50
122.0
80
176.0
-38
-36.4
-8
17.6
22
71.6
52
125.6
82
179.6
-36
-32.8
-6
21.2
24
75.2
54
129.2
84
183.2
-34
-29.2
-4
24.8
26
78.8
56
132.8
86
186.8
-32
-25.6
-2
28.4
28
82.4
58
136.4
88
190.4
-30
-22.0
0
32.0
30
86.0
60
140.0
90
194.0
-28
-18.4
2
35.6
32
89.6
62
143.6
92
197.6
-26
-14.8
4
39.2
34
93.2
64
147.2
94
201.2
-24
-11.2
6
42.8
36
96.8
66
150.8
96
204.8
-22
-7.6
8
46.4
38
100.4
68
154.4
98
208.4
100
212.0
Change 3 4-24
