What kinds of masks are there?

1, filter type

It consists of a mask and a canister (or filter element). The mask includes a mask body, an eye window, a microphone, a breathing valve and a headband (or helmet). The carbon canister is used for purifying toxic gases, and comprises a carbon canister and an adsorbent. These two materials can also be mixed to make filter plates and assembled into filter elements. A lighter canister or filter element (about 200 grams) can be directly connected to the mask, while a heavier canister is connected to the mask through an airway.

2. Isolated type

The mask itself provides oxygen, which is divided into three types: gas storage type, oxygen storage type and biochemical oxygen type. Isolated masks are mainly used in high-concentration polluted air (when the volume concentration is greater than 1%), or in special occasions such as high altitude, underwater or oxygen-deficient closed cabins.

performance test

Test method 1: Cover the exhalation valve with your palm and exhale slowly. If you feel some pressure on your face, but don't feel the air leaking from between your face and the mask, it means that you fit well. If there is leakage between the face and the mask, the headband and the mask need to be readjusted to eliminate the leakage.

Test method 2: Cover the connection port of the filter box seat with the palm of your hand and inhale slowly. If you feel difficult to breathe, it means that wearing a mask is airtight. If you feel that you can inhale air, you need to readjust the position of the mask and adjust the tightness of the headband to eliminate air leakage.

Repeat the air tightness test according to the above method 1 and 2 until the air tightness is good.