Views: 0 Author: Site Editor Publish Time: 2021-10-28 Origin: Site
General ventilation filter test method
◇ 计 计 法 ARRESTANCE
The test dust source is a large particle size, high concentration of standard dust. The main ingredient of dust is screening, the floating dust in the region, and then incorporates the specified amount of fine carbon black and short fibers. Most countries regulate the use of \"Road Dust \" (ARIZONA Roaddust) in Arizona, USA, and China standards have stipulated that the dust of a village in the Loess Plateau is used in Japan's \"Guan Dong Ascerta.\". The measured \"amount \" is the weight of the dust.
The filter is mounted in a standard test wind hole, and the upper wind is continuously dust. Every time, the dust collecting dust on the dust or filter of the filter is measured, thereby obtaining the filtering efficiency calculated by the filter at this stage according to the weight of the dust. The final weight efficiency is the weighted average of the efficiency and dust content in each test stage.
The conditions for the termination test of the courage method are: the final resistance value of the agreed, or the efficiency is significantly dropped. The so-called \"agreement \" here refers to the agreement between the customer and the trial, or the testor's own regulations. Obviously, the conditions of the termination test are different, and the weight efficiency value is different.
When the test is terminated, the weight of the filter accommodates the weight of the test dust is called \"Conditions \".
The courage method is used to measure low efficiency filters, and those filters are generally pre-filtered in the central air conditioning system.
The courage test is a destructive test and cannot be used for the daily product performance test of the manufacturer.
◇ Color Method DUST-SPOT
The test bench and the test dust were used the same as the counterweight method. Dust \"\" is the amount of light of the sample point highly filtered paper.
Sampling before and after the filter, there is high efficiency filter paper on the sampling head, obviously, the degree of contamination of the sampling point before and after the filter will be different. In the experiment, every time a dust release test is subjected to a light-light amount of the sampling point before and after the filter, by comparing the difference in filter paper light, the so-called \"filtering efficiency \" is obtained by comparing the difference in filter paper. The final colorimetric efficiency is the weighted average of the efficiency value according to the premium of the test whole process.
The conditions of the termination test are similar to the coupling conditions: the agreed final resistance value, or the efficiency is significantly dropped.
The colorimetric method is used to measure the high ventilation filter in which the efficiency is high, and most of the filters in the air conditioning system belong to this filter. The colorimetric method was a foreign test method, which gradually be replaced by the counting method. Strict colorimetric method is a destructive test.
◇ Very air dust counting method
The dust source is \"atmospheric dust \" in the natural atmosphere. The dust of the dust is larger than the number of all particulate matter equal to a certain particle size. Measuring dust is a common optical or laser dust particle counter. The efficiency value is the initial efficiency of the new filter.
The large air dust counting is used to measure the general ventilation filter. Its efficiency value represents only the performance of the new filter.
China's efficiency grading is based on a large diaphragm count.
◇ Count Method Particle Efficiency
The test bench is similar to the calculating method and the colorimetric method, and the high concentration test dust used in the dust is also similar to the counterweight method and the colorimetric method. During the \"amount \" is the number of small particle size segments. Measuring the dusty instrument is a laser particle counter.
During the test, the count measurement was performed before and after each dust test, and the filtering efficiency of the filter on various particle diameter particles was calculated. The test was stopped when the conditions of the termination test were reached. The typical efficiency value of the filter is within the specified particle diameter range, the weighted average of the transient efficiency according to each stage.
European standards stipulate that the specific multi-dispersed phase droplets used in the count measurement. US specified counting measurements use bleaching powder.
Counting efficiency is no longer a single value, but a filter efficiency curve along different particle size. European tests show that when the final resistance of the trial is 450 Pa, the count efficiency value at 0.4μ placed M is close to the conventional colorimetric value. The US standard stipulates that the filtering of different particle sizes ranges for different grades of filters, and the test final resistance is still \"2 times the primary resistance or higher \".
Complete counting efficiency test is a destructive test and cannot be used for the daily test of the product. The counting efficiency is replacing the standard color efficiency.