Can face masks help slow the spread of the coronavirus  that causes COVID-19? Yes, face masks combined with other preventive measures, such as frequent hand-washing and social distancing, help slow the spread of the virus.

How do the KN95 masks work?

Actually a type of respirator, an KN95 mask offers more protection than a surgical mask does because it can filter out both large and small particles when the wearer inhales. As the name indicates, the mask is designed to block 95% of very small particles. Some KN95 masks have valves that make them easier to breathe through. With this type of mask, unfiltered air is released when the wearer exhales.

How to test the quality of KN95 masks ？

GBPI has R&D team and technical department Independent research and development of KN95 mask testing mask including Particulate Filtration Efficiency Tester(PFE) and Respiratory Resistance Tester

Particulate Filtration Efficiency Tester(PFE)

mainly detects the particle filtration efficiency of KN95 masks

Test principle

1- Pass the particulate matter filtration efficiency tester to produce a certain concentration and particle size distribution of glue particles, and pass through the mask cover with a specified gas flow.

2- Use an appropriate particulate matter filtration efficiency tester to pass the concentration of particulate matter before and after the mask body.

3- Evaluate the filtration efficiency of the mask body on the particulate matter by the percentage of the particle concentration reduction after the aerosol passes through the mask body.

Instrument characteristics

1- Using a cold aerosol generator to produce continuous and stable aerosol particles, convenient for filling the solution.

2- Measurement of aerosol concentration using a high-precision PM2.5 sensor.

Anti-leakage design of whole particles to protect the safety of laboratory personnel.

3- Equipped with aerosol particle neutralization device.

4- The pneumatic clamp is equipped with a protection device, which is safe and convenient to use.

5- Configure temperature and humidity sensor, real-time display of ambient temperature and humidity（Temperature and humidity requirements：25℃±5℃，30%RH±10%RH）。

Equipped with glass rotor flowmeter, vacuum pump, laser dust particle counter.

6- Control system: The computer controls the test process, automatically collects data, and configures a special computer and test software.

The computer automatically tests the gas concentration and calculates the filtration efficiency. It can save, output, query and print the test data.

Respiratory Resistance Tester

Mainly detect the inhalation resistance and exhalation resistance of KN95 masks

Test principle

Under a certain air flow condition, observe the air pressure value tested by the test material to judge the inhalation resistance and inhalation resistance of the KN95 mask

Instrument characteristics

1. The instrument consists of an air source that can adjust the flow rate, a human head mold specified in the standard, two intubation systems for inhalation and exhalation, and a respiratory resistance measurement system.

2. The flow sensor has high sensitivity and has a very small starting flow.

3. The flow sensor chip uses a thermal mass flow meter, which does not require temperature and pressure compensation, ensuring high-precision measurement of the sensor.

4. Multiple sensors are integrated on a single flow sensor chip, which greatly improves the range ratio of the sensor.

5. The zero point stability of the flow sensor is high, with full range and high stability, high accuracy over the full range, excellent repeatability, low power consumption, low pressure loss and fast response speed.