I. Scope of application:
     It is suitable for the measurement of gas exchange pressure difference of masks, and can also be used to determine the gas exchange pressure difference of other textile materials.
2. Standards:
     YY0469-2011 "masks", YY0969-2013 "disposable masks".
Specifications:
    * Air source: suction;
    * Air flow: 8L / min;
    * Sealing method: O-ring seal;
    * Sample ventilation aperture: Ф25mm;
    * Differential pressure sensor range: 0 ～ 500pa;
    * Display mode: Digital display pressure difference;
    * Power: 220V, 50Hz.
Fourth, the characteristics of the instrument:
     1. Adopt suction air source as the power source of the instrument, not limited by the space of the test site;
     2. Equipped with a precision differential pressure sensor, which digitally displays the pressure difference on both sides of the sample;
     3. The special sample holder ensures that the sample is firmly held.