Brief description of leakage rate test process of gas mask

author: Source
28/08/2021
image

Applicable standard for leak rate test instrument of gas mask: gb2890-2009 standard, 4 test samples, 2 untreated samples and 2 pretreated samples.

Test process:

Conditions:

1. Each mask shall be worn and tested by 10 persons whose head and face dimensions meet the requirements according to its adaptation range, and the subjects shall shave their beard. The mask shall be worn to the extent that the subject feels appropriate, and the headband adjustment shall not be too tight or too loose.

2. Detect the oil mist concentration in the warehouse 150 ~ 200mg / m ³。

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 sampling tube in the inspection chamber shall be located in the moving area of the subject's head. The sampling tube shall be installed on the tested sample, the interface shall be kept airtight, and the tube end shall be close to the mouth and nose area.

Steps:

1. Pass the oil mist into the detection chamber, adjust the concentration to the stable concentration required by the test, start the air extraction pump, and the air flow concentration is measured by the photometer.

2. The subjects wear masks correctly, conduct preliminary air tightness inspection according to the use method, adjust properly, and connect the sampling pipe to the photometer.

3. Start the air pump, measure the air flow concentration in the mask when the subjects breathe in the smoke free air outside the inspection chamber, take 5 numbers, and the average background concentration.

4. Make the subject enter the detection chamber and complete the following actions according to the instructions. Measure the concentration of air flow in the mask under each action, with 5 data each, and the average value is taken as the leakage concentration of the action.

a. Calm state for 1min

b. Swing the head up, down, left and right for 1min

c. Speak for about 1min

result:

1. The leakage rate of full mask shall not be greater than 0.05%

2. The leakage rate of half mask shall not be greater than 2%