Operational Alert

TM 3-6665-225-12

(24) Connect power source connector to M43

(12) Press and hold ZERO ADJUST knob (5,

detector unit 24 VDC INPUT connector (11, fig. 1-2).

fig. 2-1) in. Press in hand crank (2), rotate crank

(25) Press and adjust ZERO ADJUST knob (5,

clockwise 50 turns, and release it.

fig. 2-1) so that meter (1) indication is within blue

NOTE

ZERO ADJUST zone. Then release knob. Repeat

Keep hand crank in down position, not

after 5 minutes.

pressed in.

(26) Twist FLOWMETER (2, fig. 2-6) clockwise

(13) Press and rotate ZERO ADJUST knob un-

and remove it from AIR INLET assembly cover (4).

til meter (1) indicates in ZERO ADJUST zone (blue).

Install FLOWMETER in M43 detector unit handle.

Release knob. After 5 minutes, press and reset, if ne-

(27) Rotate AIR INLET assembly to OPEN

cessary.

position (fig. 2-5, B).

(14) Disconnect power source connector from

CAUTION

M43 detector unit 24 VDC INPUT connector (11,

To prevent damage by overheating, never

fig. 1-2).

operate M43 detector unit with AIR IN-

(15) Remove protective cap from sensitivity

LET assembly in CLOSED position and

check bottle (6, fig. 1-6). Unscrew AIR FILTER plug

AIR INLET plug (1) installed.

(4, fig. 2-4) and remove air filter (3).

(28) Install and secure AIR INLET plug (1), or

(16) Invert sensitivity check bottle and, while

if M43 detector unit is mounted on a vehicle, re-

holding dropper tip 1/2 inch over center of black

move RAINSHIELD assembly (1, fig. 1-3) and in-

side of filter material (2), allow two drops of solu-

stall and secure it in cover (4, fig. 2-6).

tion to fall on filter.

NOTE

(17) Immediately replace air filter (3) in M43

The alarm system is now operational.

detector unit and secure AIR FILTER plug (4). Re-

2-11. Operational Alert

place cap on sensitivity check bottle.

NOTE

(18) Connect power source to 24 VDC INPUT

The M43 detector unit will signal when

connector (11), fig 1-2) of M43 detector unit.

exposed to heavy concentrations of rocket

(19) Immediately press and hold ZERO AD-

propellant smoke, screening smoke, signal-

JUST KNOB (5, fig. 2-1) for 5 seconds and release

ing smoke, engine exhaust, or in the event

it. Within 15 seconds to 5 minutes, M43 detector

of nuclear explosion.

unit horn (3) must sound.

When the alarm system signals the presence of

NOTE

chemical agents, perform the following:

If M43 detector unit horn does not sound,

a. Immediately take protective measures pre-

repeat (13) through (19) above twice, if

scribed in FM 21-41.

necessary. Use a new filter each time. Then

b. Give local alert as prescribed by local stan-

refer to table 3-3 for operator's trouble-

ding operating procedures (SOP).

shooting information.

c. Disconnect power source from M43 detector

(20) Disconnect power source connector from

unit 24 VDC INPUT connector (11, fig. 1-2).

M43 detector unit 24 VDC INPUT connector (11,

fig. 1-2).

d. Set AIR INLET assembly cover (4, fig. 2-5) to

(21) Remove AIR FILTER plug (4, fig. 2-4) and

CLOSED position (fig. 2-5, A). Remove RAIN-

SHIELD assembly (1, fig. 1-3) from cover, if used.

discard used air filter (3). Open unused air filter

package (7, fig. 1-6), discard watertight bag (8).

Install electrical connector cover (10, fig. 1-2) on 24

VDC INPUT connector (11). Install AIR OUTLET

Remove air filter (10) from plastic wrapper (9) and

cap (15) on AIR OUTLET port of M43 detector unit.

discard plastic wrapper.

CAUTION

(22) Insert air filter (3, fig. 2-4) into AIR FIL-

Do not remove bottom case assembly (9) in

TER slot of M43 detector unit (1) with black side of

filter material upward. Install and tighten AIR

presence of chemical agents. Exposure to

chemical agents will render the M43 de-

FILTER plug (4).

(23) Position M42 alarm unit selector switch (8,

tector unit useless. Chemicals used for de-

fig. 1-5) to HORN ON or connect wire to M43 de-

contamination will damage the interior of

tector unit REMOTE binding post (17, fig. 1-2).

the M43 detector unit.

Change 2

2-9