What are the testing methods of the 8 Best high efficiency filters?
SFFILTECH believes that from the evolution of international high efficiency filter testing standards, it can be seen that the test methods for high efficiency air filters are mainly sodium flame method, oil mist method, DOP method, fluorescence method and particle counting method.
(1) Sodium flame method
Sodium flame method originated in 1969 in the United Kingdom, some European countries in the 1970s to 1990s, is one of the current national standard methods in China. The method can only detect the sensitivity is not high, can not be detected on the ultra-high efficiency filter.
(2) Oil mist method
Oil mist method originated in Germany, China and the former Soviet Union also implemented. Oil mist method in the detection of filters, easy to cause damage to the filter, and can not directly read the value, wasting time, has rarely used.
(3) DOP method
DOP method originated in 1956 in the United States, has been adopted by many countries, China’s national standards have also been used, this method was once the most common method of testing high efficiency filters internationally. The measurement instrument is mainly light scattering photometer.
(4) Fluorescence method
The fluorescence method is only used in France. The test dust source of the fluorescence method is sodium fluorescein dust generated by the sprayer. The test method is to first sample before and after the filter, and then measure the fluorescence brightness of the aqueous solution containing sodium fluorescein under specific conditions, from which the filter filtration efficiency is calculated. France has long since not used the fluorescence method, and some nuclear industry systems currently use the fluorescence method for on-site testing of filters.
(5) particle counting method
This method is common in Europe, and the U.S. ultra-high efficiency filter test method is also relatively similar, and is currently the mainstream test method internationally. The entire air outlet surface of the filter is scanned and inspected with a counter, which gives the number of dusts at each point and also compares the local efficiency of each point.
SFFILTECH thinks it is also a good method to test the quality of high efficiency filter with water, just put the air filter flat on the floor or table and sprinkle some water on top of the filter paper to observe the state of water.
(1) If the filter paper seeps into the water within 5 minutes, it is the air filter made of cotton pulp paper (shoddy filter paper), which should never be used, this air filter is mostly produced in Hebei, and there are a few cheap people using it in the air compressor industry.
(2) If the filter paper seeps into the water within 2-5 hours, it is made of low-grade wood pulp paper and can be used, but it will reduce the efficiency of air compressor gas production and lead to more power consumption of air compressor. Since the price of air filters made of this kind of filter paper is relatively low, and they can also be used, so now the 8 Best high efficiency filters of this kind of filter paper in the air compressor industry are in the mainstream, and most air compressor stores are selling this kind of air filters.
(3) If the filter paper 12-15 hours before water seepage into the filter paper belongs to the better filter paper, usually a better quality of the domestic machine factory to use this type of filter paper air filter to do the original consumables.
(4) If the filter paper does not seep in for 24 hours, it is definitely a high-grade filter paper, and usually high-grade OEMs use this type of filter paper as the original consumables.