TM-9-2350-311-10

HOWITZER, MEDIUM, SELF-PROPELLED, 155MM; M109A2, M109A3, M109A4 AND M109A5

TECHNICAL MANUAL; OPERATOR’S MANUAL

NOVEMBER 1994

TM-9-2350-311-10 - Page 367 of 775

TM 9-2350-311-10

2-17 OPERATING AUXILIARY EQUIPMENT — CONTINUED

2-17.6 NBC Equipment (M109A4/M109A5 Howitzers) — Continued

d. NBC Filter Change Criteria

NBC protective clothing and equipment are required for filter change. Crew members should not

change filter elements. Filter element change requires coordination with an NBC qualified

non-commissioned officer (NCO) or officer. Notify unit maintenance.

1

If the following conditions exist, notify unit maintenance to replace gas filter:

• Physical damage

• Filter becomes wet or clogged

• Higher authority directs replacement of gas filter

• Annual service time

• At beginning of combat operation where use of blood agent (AC or CK) is expected

•. After every known blood agent attack

2

If the following conditions exist, notify unit maintenance to replace particulate filter:

• Physical damage

• When gas filters are changed

• Particulate filter becomes clogged, causing insufficient air flow

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