The gas exchange pressure difference test machine is also called disposable medical mask ventilation resistance tester

1. Measuring principle of gas exchange pressure difference tester:

1.1. Use a device that measures the pressure differential required to inhale air through the measurement surface area at a constant air flow to measure the air exchange pressure of the medical mask material. A differential pressure gauge filled with water (or digital) is used to measure the differential pressure. Mass flow meters are used to measure air flow. The electric vacuum pump draws air through the test equipment, and the needle valve is used to regulate the air flow.

2.The measurement and test device of the gas exchange pressure difference test machine:

2.1. Mass flow meter capable of measuring air flow of 8 liters / minute.

2.2. Pressure gauge, differential pressure gauge (water or digital). A separate pressure gauge can also be used. M1 is used for upstream pressure measurement, and M2 is used for downstream pressure measurement.

2.3. Electric vacuum pump, including pressure buffer tank.

2.4. Valves that allow flow regulation.

3.The sample rack measured by the gas exchange pressure difference testing machine:

3.1The sample holder should consist of a mechanical clamping system and the alignment of the top and bottom brackets.

3.2. The sample holder should include a mechanism to adjust the clamping pressure. A threaded system can be used on the bottom or top of the sample holder.

3.3. The inner diameter of the top support and the bottom support in the area in contact with the filter material should be (25 ± 1) mm.

4.The sealing of the top and bottom brackets on the filter material should consist of metal-metal contacts:

4.1 A metal ring with an inner diameter of (25 ± 1) mm. 3 mm thick will be fixed on the top bracket.

4.2 The bottom bracket will consist of a completely flat metal surface with an inner surface of (25 ± 1) mm, and a 4.3 mm area of 3 mm will be formed around the diameter of the opening. Materials such as rubber or foam do not provide sufficient sealing and may deform into the test area.

5. Verification of test equipment should include leak testing. The second flow meter immediately before the valve will allow the assessment of air leakage in the test equipment. With the sample holder closed, start the pump and adjust the flow meter so that it reads 8 l / min on the first flow meter. If there is no leakage, the readings of the two flowmeters should be 8l / min:

5.1 When both flowmeters reach 8l / min, another check should include stopping the air intake. After a few seconds, if there is no leak, the two flow meters should indicate 0.l / min.

GBPI is a national new technology enterprise and a model unit of China's credit enterprise. It is committed to the research and development and production of packaging testing instruments and mask testing equipment. The company has a large production plant, as well as multiple marketing centers, logistics centers and after-sales centers. The company's staff are professionals who have been in the inspection field for 20 years. They have rich testing experience and strong technical force, and can provide you with professional personalized customization and system solutions.