Test Method for total leakage rate of medical protective masks
Respiratory protection Self-priming filter respirator against particulate matter
Prepare the sample to be tested and install the sampling tube. The installation position of the sampling tube should be as close as possible to the position directly in front of the user's mouth and nose.For on
When the mask is discarded, necessary measures should be taken to prevent the sampling tube from affecting the position of the mask during the test;When applicable, connect the KP100 level filter
Components.Check the testing system to make sure it is in normal working condition.
The particulate matter will be detected in the warehouse to make its concentration meet the requirements.
Subjects will wear the tested sample in the clean air area, and check the air tightness of wearing according to the usage, and then connect the sample tube to the particulate matter
In the detector, background concentration in the mask during the detection of the subject's outside of the chamber breathing was measured. Five data were measured and the arithmetic mean value was taken as background concentration.
Let the subject enter the human detection room and connect the sampling tube to the particle detector under the condition of avoiding particle pollution;And then the subject presses
Complete the following actions in order of time :
A) The head is silent and silent for 2 min;
B) Turn the head left and right to look at the left and right walls of the detection warehouse (about 15 times) for 2 min;
C) Look up and down at the warehouse items and the ground (about 15 times) for 2 min;
D) Read aloud -- paragraphs of text (such as counting Numbers), or speak loudly for 2 minutes;
E) the head is stationary and does not speak for 2min.
During each action, the concentration of particulate matter in the capsule and the mask should be detected simultaneously.- Generally, only the last 100s time was measured
Block fields to avoid detecting crossed sections of actions.For each action, five data should be detected and the arithmetic mean calculated as the action's.
The results.
Subjects are allowed to adjust the mask they wear during the test, but the test for this action should be redone.
The replaceable face mask should be cleaned or disinfected as recommended by the manufacturer before being used for the next subject.
When NaCl particle detection is adopted, the total leakage rate of each action in the detection of disposable mask and each action of replaceable mask are detected
Leakage rate is calculated according to Equation (3) :
Type:
C. The concentration of particulate matter in the mask measured during each movement is in milligrams per cubic meter (mg/m3);
C.Background concentration of particulate matter in the face mask measured in milligrams per cubic meter (mg/m*);
When Co does each action, the concentration of particulate in the warehouse is detected in milligrams per cubic meter (mg/m3);
1.7- Correction factor for reduced particle concentration in respirator mask caused by sodium absorption and vaporization in the subject's respiratory tract.
When oil particles are used for detection, the total leakage rate of each action and the leakage of each action of the replaceable mask are detected
The leakage rate is calculated according to Equation (4) :
Type:
C. The concentration of particulate matter in the mask measured during each movement is in milligrams per cubic meter (mg/m3);
C。.Background concentration of particulate matter in the face mask measured in milligrams per cubic meter (mg/m*);
Co. when does each action, the concentration of particulate in the warehouse is detected in milligrams per cubic meter (mg/m3);
1.7- Correction factor for reduced particle concentration in respirator mask caused by sodium absorption and vaporization in the subject's respiratory tract.
When oil particles are used for detection, the total leakage rate of each action and the leakage of each action of the replaceable mask are detected
The leakage rate is calculated according to Equation (4) :
C. The concentration of particulate matter in the mask measured during each movement is in milligrams per cubic meter (mg/ m3);
C。.Background concentration of particulate matter in the mask measured in milligrams per cubic meter (mg/m3);
C0.As soon as each action is done, the concentration of particulate matter in the warehouse is detected in milligrams per cubic meter (mg/m3).
The total leakage rate or total leakage rate of each subject calculated by person is calculated according to Formula (5) :
