III–B–1

S-Filter

The purpose of the canister is to remove chemical warfare agents from the atmos-phere, when used in conjunction with a facepiece.

All S canisters, regardless of the type, usually have a paper label around the circum-ference of the canister at the base, with various inscription, including "S-Filtereinsatz für den zivilen Luftschutz". The top of the canisters are generally marked with an "F" and a multitude of goverment and manufacturers' stampings and stencillings.

There are number of types of this canister, all of which have similar fillings but differ somewhat in external appearance. One type is illustrated on the opposite page. All of the canisters are of the snout type, either of gray or green lacquered tin plate. The green lacqured type, as illustrated in the drawing, measures 3.4 inches in height and 4.2 inches in diameter. The gray lacquered type resembles Model B of Canister, GM, Impregnatedm No. III–B–3. The canisters are manufactured from two sections of tin plate; the upper section consists of the externally threaded neck and all of the sides of the canister down to the base, and the second section consists of the perforated flat base. When new, the base is covered with a wax paper covered cardboard seal, to which is attached a metal pull ring for removing the seal prior to initial use. A threaded metal cap is also provided for sealing the neck.

A sectionalized view of one of the canisters shows the three layers of filling common to all of the S canisters. The top layer, A, is composed of brown diatomite brick granules impregnated with potassium carbonate and hexamine, the next layer B, or shell or extru-ded charcoal, and the bottom layer, C, of a white or bluish-white cottonasbestos pad.

III–B–1