Lesson 2/Learning Event 4
NBC Equipment Preventive Maintenance Indicators
Preventive maintenance indicators are selected inspection points which, as the name implies,
indicate, but do not completely establish or confirm, the preventive maintenance status (readiness
condition) of the equipment. Their use is a sampling technique. The indicators represent
sampled inspection points. Indicators of this type are intended for use by the nonspecialist and,
particularly, by the commander himself They are not a substitute for a thorough inspection by
maintenance personnel. As the unit NBC defense officer or NCO, you will need to know
specific points to inspect, or to recommend that the commander inspect on NBC equipment.
Some specific checks to make on NBC equipment commonly found in units are discussed below.
IM-174 Series Radiacmeters. Points to check on IM-174 Series Radiacmeters are listed below.
Battery Box. Check for dirt or evidence of leakage; a worn, cut, or broken O-ring a worn,
broken, or kinked battery cable.
Battery Check. Check that the switch is set to linearity, and that the meter pointer does not
indicate within the red mark.
Zero Adjust. Check that the switch is held in the zero position, that the meter cannot be adjusted
to zero; check that the switch does not spring back to the check position when released.
Carrying Case and Strap. Check that the carrying case and the strap are not torn or broken, that
the snap fasteners are not dirty or loose fitting, that the clips and rings are not broken or bent, and
that the plastic window is not broken or discolored.
Meter and calibration control caps. Check that the meter windows are not dirty,
broken, or missing; that the meter does not indicate when held near a source or test sample; and
that the calibration control caps are not missing or loose.
M17-series Protective Masks. NBC defense officers and NCOs are responsible for checking the
condition of the protective masks in a unit. They are NOT responsible for cleaning individual
masks. This is the responsibility of each soldier. To check the M17-series Protective Mask, you
would look for--
wet or visibly damaged filter elements.
inelastic, cut, or torn head harness.
nosecup valve disks not in place.