What is the principle of the mask vision tester test?

The mask visual field tester is used to test the visual field effects of daily protective masks, masks, gas masks, etc. It is suitable for labor safety and protection inspection centers, medical device and drug inspection centers, disease prevention and control centers, textile testing centers, masks and mask manufacturers, etc. Mainly used to evaluate the effective field of view of full face mask, half face mask or other respirators. Put the mask on the dummy's head, shine the lights in each eyehole of the dummy's head, and use the photometer to trace the shadow curve of the translucent part of the device. Both total and overlapping fields of view can be measured simultaneously.

Mask vision tester test principle:

 

Install a low-voltage light bulb at the eyeball position of a standard head shape, so that the solid angle of the light is equal to the solid angle of the average Chinese adult's field of vision. After wearing the mask, the outgoing light cone is limited by the mask and shrinks, and the preserved percentage is equivalent to the visual field preservation rate after the standard head shape wears the mask. Use the perimetry to measure the field of view after wearing the mask. Measure the total visual field area of the two eyes and the binocular visual field area of the common part of the two eyes, find their corresponding percentages when not wearing a mask, and use the correction coefficient to get the total visual field preservation rate and binocular visual field preservation Rate.

 

Mask vision tester operation process:

 

1. Put the test mask on the head mold, make the left or right eye at the center of the arc, and turn on the light bulb

2. Measure a point every 30 degrees in vertical or horizontal orientation.

3. Move the headform, measure and record the other eye.

4. Take off the mask and repeat the test 3 times.

5. Connect the left and right field of view into a closed curve

6. Use the planimeter to record the binocular field of view and the total field of view, and judge according to the standard.