FED-STD-228A
TABLE I. Current in heater coil
Nominal diameter of specimen (inches)
Current
amperes
a. c. (r. m. s.)
0.1
46
.2
47
.3
48
.4
49
.5
50
.6
51
.7
52
.8
53
.9
54
1.0
55
1.1 to 1.3
56
1.4 to 1.7
57
1.8 to 2.2
58
2.3 to 2.9
59
3.1.7 Watch or other timing device which will register the time in seconds.
4. PROCEDURE
4.1 Time of heating.
4.1.1 Unless otherwise specified in the detail specification, for all armored cables, whether tested with or
without armor, the current in the heating coil shall be turned off 30 second after ignition occurs.
4.1.2 Unless otherwise specified in the detail specification, for all unarmored cables, where the ignition
time is less than 60 seconds, the current in the heating coil shall be turned off 60 seconds after being
turned on.
4.1.3 Unless otherwise specified in the detail specification, for all unarmored cables, where the ignition
time is greater than 60 seconds, the current in the heating coil shall be turned off when ignition occurs.
4.2 The lower end of the specimen shall be wrapped with varnished cambric or similar material in such a
manner that any gases released through this end shall be diverted toward the spark plugs.
4.3 Time of ignition. The specimen shall be centered in the heater coil. The spark plugs and flame gage
shall be placed in position and the chamber shall be closed and the ventilating fan started. The watch or
timing device shall be started simultaneously with the energizing of the heater coil by the current as
specified in table I and the energizing of the spark plugs. Ignition shall be considered as occurring when
the flame transfers from the escaping gases to the surface of the specimen and continues there. Flashes
which may occur in the gaseous space prior to obtaining a sustained flame shall be disregarded. The
time from the starting of the current until ignition shall be recorded as the ignition time.
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