Preparation Test Specimens:
A minimum of three fabric specimens should be taken diagonally across the width of the fabric to be representative of the material.
Cut specimens at least 200x200 mm to allow properclamping.
Handle the specimens as little as possible and avoid folding or contaminat-ing the area to be tested.
Condition the test specimens at 21 – 2°C (70 – 5°F) air at 65 – 2% RH for at least 4 h before testing.
The surface of the fabric to be ex-posed to water must be specified because different results may be obtained on the face and the back. Identify that surface on a corner of each specimen.
Hydrostatic Pressure test Procedure:
The test sample cut into 100mm × 100mm size , and then put the sample into the fixture, tighten the fixture fixed. Press the up button, the metal container containing 700ml of water starts to rise at the same speed as the motor. The water pressure is increased by the specimen in the fixture. The color of the paper is measured by the plastic window covering the filter paper penetration.
When the initial signal indicating the change of the color of the paper (from blue to pink) appears, the height of the scale should be readed immediately, expressed in Pa (mmH20), and press the rising button again to stop the metal container from rising. Record the reading as test data for the impermeability of the filter paper.
Open the fixture, remove the sample and indicator paper, wipe the fixture with a soft cloth, check the waterlevel in the fixture. If necessary, reinstall the water. Use another sample and indicator paper to place the fixture again and repeat the above test procedure for testing.
If the installation of instructions paper, indicating the preparation of paper can refer to GJB 1152-9l "military efficient air filter paper general specification" of the relevant provisions.
Note the question:
1, after doing an anti-seepage test, press the drop button to make the metal container down to the initial position of the ruler, press the drop button again to stop, ready for the next test.
2, through the inverter panel to adjust the frequency, thereby changing the metal container rising speed.
