TM9-1375-213-12
NSN 1375-00782-5541
wound dc generator, the machines use a small alterna-
DA-11-173-AMC-499(A)
tor which is gear-driven by the handle-actuated plung-
DIXSON, INCORPORATED
er. The electrical output from the alternator is re-
GRAND JUNCTION, COLORADO, U.S.
flected and fed into storage capacitors. When suffi-
cient energy is available in the capacitors (this may
(NEWER 50-CAP MACHINE)
take three or four strokes of the handle), an internal
STOCK NO. 1375-141-9495
switching circuit discharges the electrical energy to
CONT. NO. DA-11-199-ORD-1083
the output terminals, and thus to the blasting circuit.
U.S.
If there is no blasting circuit attached to the terminals,
BLASTING MACHINE
this energy will be discharged through an internal by-
SERIAL NO.
CAPACITY
pass, The impact-resistant plastic housing completely
A4375
50 CAPS
seals the machine against sand, dust, and dirt, mud
COPPER WIRES TO 30FT.
and even total immersion in three feet of water. The
OR IRON WIRES TO 6 FT EACH
terminals, spring-loaded Signal Corps type, allow rap-
CONNECT BLASTING CAPS ONLY IN SERIES
id and positive connection of the firing lead conduc-
TO FIRE
tors. A D-ring clip on the base of the machine is used to
RAISE HANDLE UNTIL IT STOPS:
hold the handle against machine body. The plunger is
PUSH DOWN QUICKLY WITH
spring-loaded so that, when free form the D-ring clip,
FULL FORCE.
the handle is in the READY-TO-FIRE position (sway
FIDELITY ELECTRIC CO. INC.
from machine body). Another D-ring clip is used for
LANCASTER, PA.
carrying the machine on a belt clip. A neon indicator
(1) Generator-type machines. The generator-type
lamp is located within the plastic housing between the
machines, described individually below, are all actua-
terminals. When the machine is successfully actuated,
ted by means of a gear-driven armature. The 10-cap
a momentary glow is normally visible through the
machines have metal cases and twist-type handles,
housingwhether or not a blasting circuit is attached
with cases and handles painted gray, black or olive
to the output terminals.
drab. The higher capacity machines have varnished or
painted wood cases and plunger-type handles. Two dis-
only two instruments currently authorized for check-
tinct generations of generator-type machines are in
ing blasting circuits are the blasting galvanometers and
existence as follows:
test set M51. Both instruments are used to check cir-
(a) Newer machines (10-cap and 50-cap).
cuit continuity; however, the blasting galvanometer,
NOTE
which uses the special battery, has the additional capa-
The machines most often used for electric
bility of indicating the approximate resistance of the
blasting operations are the 10-cap and 50-
circuit. Test set M51 does not require a battery and is
cap machines.
usable over a wider range of temperatures.
In addition to having significantly higher electrical
(1) Galvanometers, blasting. The blasting galva-
output than their predecessors, these machines include
nometers (A, fig. 1-4 1) is a small instrument for check-
a built-in safety circuit. This circuit allows no current
ing the continuity and determining the approximate
to reach the terminals until the machine's handle (or
resistance of electrical blasting circuits. It works by
plunger) has been actuated with sufficient energy to
sending a minute amount of current from a silver
gain nearly the maximum output from the machine.
chloride battery through the blasting circuit and
Therefore, unless such as level of output is reached, no
through a D-Arsonval meter. The meter's needle re-
current will flow to the terminals.
sponds in proportion to the amount of resistance the
(b) Older machines (10-cap, 30-cap, 50-cap, and
current encounters in the blasting circuit. Type of bat-
100-cap). These include a switch which delays the flow
tery authorized is dependent on operating tempera-
of current from the generator to the terminals until
tures, and is listed below:
the handle (or plunger) is near the end of its travel.
Normal temperatures
Silver chloride dry
This switch assures that output produced by machine's
(0F. to + 125F.)
cell, MIL type
mechanism does not reach the terminals until the op-
BA-245/u.
erator is producing maximum force. The older 10-cap
Low temperatures
Silver chloride dry
machine is known as the Fidelity-type machine, since
(-20F. to 0F.)
cell, MIL type
it was primarily manufactured by Fidelity Electric
BA-2245/u.
Company.
(2) Test set, blasting cap: M51. Test set M51 (B,
(2) Blasting machines M32 and M34. These small,
lightweight blasting machines are intended to replace
developed as a replacement for the blasting galvanom-
the larger, heavier machines. Instead of the shunt-
eters to test continuity of electrical blasting circuits.
Change 5
