Brief introduction to the test process of gas mask leakage rate

Applicable standards for the gas mask leakage rate testing instrument: GB2890-2009 standard requirements, 4 test samples, 2 for untreated samples, and 2 for pretreated samples.

Testing process:

condition:

1. For each mask, select 10 persons whose head and face size meet the fitting test for wearing test. The subjects need to shave their beards clean. The mask should be worn to the extent that the subject feels comfortable, and the headband adjustment should not be too tight or too loose.
2. The oil mist concentration in the detection chamber is 150-200mg/m³.
3. The oil mist filtration rate of the filter element is higher than 99.995%. If the manufacturer does not have a filter element with this oil mist filtration efficiency, it is allowed to replace it with a filter element higher than 99.995% during the test.
4. The position of the sampling tube in the inspection chamber should be located in the active area of the subject’s head. The sampling tube is installed on the sample to be tested, the interface is kept airtight, and the tube end is close to the mouth and nose area.

step:

1. Pass the oil mist into the detection chamber, adjust the concentration to the stable concentration required by the test, start the air pump, and measure the airflow concentration by a photometer.
2. The subject wears the mask correctly, conducts a preliminary airtight inspection according to the method of use, and adjusts the sampling tube to the photometer properly.
3. Start the air pump, measure the airflow concentration in the mask when the subject breathes in the smoke-free air outside the inspection chamber, take 5 numbers, and get the average background concentration.
4. Let the subject enter the testing chamber and complete the following actions according to the instructions, measure the concentration of the airflow in the mask under each action, 5 data for each, and the average value is taken as the leakage concentration of the action.

a. Calm state for 1min

b. Shake the head up and down, left and right for 1 minute

c. Speak for about 1 minute

result:

1. The leakage rate of the full mask is not more than 0.05%
2. The leakage rate of the half mask is not more than 2%