Views: 3 Author: Site Editor Publish Time: 2021-07-12 Origin: Site
High efficiency filterMainly filtered by the end filtration of the filter system of clean room or dust-free workshop, is an important filter that is directly related to air cleanliness. The efficient filter leaks as one of the projects detected by clean workshops, the purpose of its detection is to detect the high-efficiency filter and its sealing at the installation framework connection, and timely discover the shortcomings of the high-efficiency filter itself and the installation. Take the corresponding remedial measures to ensure the cleanliness of the area.Then we will introduce you to the method of leak detection of high efficiency filter:
First, sodium flame method
The test dust source of the sodium flame method is a multi-dispersion phase chloride salt, \"amount \" is the brightness of the hydrogen flame when salt-containing fog burning.
The brine splashes at the agitation of the compressed air, and dried over the fine salt crystal particles and enters the airway, sampled before and after the filter.
The salt-containing gas samples make the color of the hydrogen flame, the brightness increases, and determines the salt mist concentration of the air in the brightness of the flame, and determines the filtration efficiency of the filter on the salt mist.
The main detection instrument is a flame photometer, which can only have a sponge to detect the sensitivity, and cannot be superHigh efficiency filterDetection.
Second, oil mist
The oil fog method is the oil mist, \"amount \" is the turbidity of oil-containing air, and the filtering efficiency of the filter on the oil mist particles is judged by the turbidity difference of the gas sample before and after the filter.
Germany stipulates that paraffin oil is used in Germany, the oil mist particle size is 0.3 to 0.5 microns. Oil foam method When detecting a filter, it is easy to cause damage to the filter and cannot be read directly, and time is wasted.
Third, DOP method
This method is once the international testHigh efficiency filterSponge common method.
Its test dust source is 0.3 micron single-dispersed adjacent benzene dictyl dictyl (DOP) droplets, also known as \"hot dop \", \"\ \" is a turbidity of DOP air.
The DOP liquid is heated into steam, and the steam is condensed into a small droplet under certain conditions. After the excessive and too small droplets leave 0.3 microns, the airway is entered, and the turbidity of the gas sample before and after the filter. And thereby judged the filtering efficiency of the filter to 0.3 microns dust.
The fluorescence method is tested for the dust source for the fluorescein powder produced by the sprayer.
The test method is first after the filter sponge, then the fluorescery sodium on the sampling filter paper is then used to measure the fluorescence brightness of the fluid-containing aqueous solution under certain conditions, the weight of the luminous reaction, thereby calculating the filter Filtering efficiency.
V. Particle counting method
This method is common in Europe, and the US ultra-efficient air filter test method is also a relatively similar, and it is currently the mainstream sponge test method.
The dust source is a multi-dispersed phase droplet, or determines solid dust of the particle size. Sometimes the filter manufacturers should use atmospheric dust or other specific dust in accordance with the special requirements of the user.
If the condensed nuclear counter is used in the test, a single scattered phase test of a particle size must be used. The main measuring instrument is a large flow laser particle counter or a condensate core counter.
The entire out of the filter is scanned with the entire wind surface of the filter. The number of dust per point is given, and the local efficiency of each point can be compared.