Figure 9-6.--M42 remote alarm connected to M43 detector.
NAAK, Mark I
This unit is the primary means of detecting chemical
agents arriving in a unit area from an upwind chemical
Three NAAK, Mark I, injectors are carried by the
attack. It can detect chemical agents in vapor and aerosol
individual in the top outside pocket of the mask carrier.
form and can alert personnel by audible and visual
These injectors are used for nerve agent first aid. This
signals. It is issued to platoons, companies, and similar
solution has a relatively high-freezing point and should
be removed from the carrier and placed inside the field
uniform in cold weather (below 45°F).
The M43 detector unit of the automatic chemical
agent alarm continuously samples the air at its location
CBR UNIT EQUIPMENT
and indicates the presence of nerve agents. The M43
gives an audible alarm. The M42 remote alarm unit
Each Seabee unit should have the equipment
provides both an audible and visual alarm when
connected by wire to the M43 detection. The M42 audible
alarm can be turned off manually. Up to five M42s can
Automatic Chemical Agent Alarm M8A1
be connected to the M43 (fig. 9-6). Maximum cable
length must not exceed 400 meters from the detector to
The M8A1 automatic chemical agent alarm consists
of the M43A1 detector unit and the M42 alarm unit.
the farthest alarm.