Use of Spectacles

TM 3-4240-212-14&P

Bausch and Lomb Standard, Semi-Rimless, Highland Bal-

are in the canister or until the oxygen-producing chemical

Grip. Personnel who must wear spectacles while using

is expended even if the apparatus is not being worn. The

the apparatus should request them from the medical

generated oxygen flows from the canister into the

officer in charge. The spectacles should meet the

breathing bag. The heat evolved during the chemical

following specifications:

reaction is dissipated as the breathing mixture circulates

in the breathing bag.

(1)

Eye size ............................ 42 to 46 mm

c. When the operator inhales, air is drawn from the

(2)

Bridge ............................. 18 to 24 mm

breathing bag through the inhalation breathing tube, the

(3)

Lens prescription plastic (CR-39), oval shape

inhalation valve in the facepiece valve assembly, and

(4)

Temple ............ size 5 1/2 in to 7 in., type CC,

then into the facepiece. A pressure relief valve in the

plain. U15b, flat without

facepiece valve assembly allows the operator to release

embossment

any excess pressure that builds up in the breathing

apparatus.

b. When wearing spectacles with the apparatus, the

M20 OBA hood must be attached to the facepiece.

1-7.

Use of Spectacles

a. Of the spectacles tested, the only ones found to

satisfactory for use with the breathing apparatus are

1-8