HEPA is High Efficiency Particulate Air, so a HEPA filter is a High Efficiency Particulate Air Filter, also known as high-efficiency particulate absorbing filter and high-efficiency particulate arrestance filter,is an efficiency standard of air filter.
Filters meeting the HEPA standard must satisfy certain levels of efficiency. Common standards require that a HEPA air filter must remove-from the air that passes through-at least 99.95% (ISO, European Standard) or 99.97% (ASME, U.S. DOE) of particles whose diameter is equal to 0.3 μm, with the filtration efficiency increasing for particle diameters both less than and greater than 0.3 μm.[8] HEPA filters capture pollen, dirt, dust, moisture, bacteria (0.2-2.0 μm), virus (0.02-0.3 μm), and submicron liquid aerosol (0.02-0.5 μm).[11] Some microorganisms, for example, Aspergillus niger, Penicillium citrinum, Staphylococcus epidermidis, and Bacillus subtilis are captured by HEPA filters with photocatalytic oxidation (PCO). HEPA is also able to capture some viruses and bacteria which are ≤0.3 μm. HEPA is also able to capture floor dust which contains Bacteroidia, Clostridia, and Bacilli. HEPA was commercialized in the 1950s, and the original term became a registered trademark and later a generic trademark for highly efficient filters. HEPA filters are used in applications that require contamination control, such as the manufacturing of hard disk drives, medical devices, semiconductors, nuclear, food and pharmaceutical products, as well as in hospitals, homes, and vehicles.
HEPA Filter is divided intoDeep-pleated HEPA filter and Mini-pleated HEPA filter.
Deep-pleated HEPA filter
Specialty:
* Collecting 0.3 Micron or below particles and used as the terminal filtration.
* Deep-Pleated HEPA filter is processed by super fine fiberglass media or PP media separated by sized paper or aluminum foil with new polyurethane gasket, there is MDF, galvanized steel, stainless steel, aluminum frame available.
* Each HEPA Filter is individually tested via PSL particle, Using MPPS (DOP Test) laser particle counting device to measure overall efficiency of the filter.
* It is featured with high efficiency, low resistance, high dust holding, long working life, easy installation.
* Temperature resistance: 80℃, relative humidity is 80%.
Application:
It is widely used as terminal filter in top grade purifying equipments of Electronics Factory, semiconductor, precision, mechanism, pharmaceutical factory, hospital, food sanitation etc.
Mini-pleated HEPA filter
Specialty:
* Mini-pleated HEPA filter can collect 0.3 Micron or below particles and used as the terminal filtration.
* It is processed by super fine fiberglass media separated by hot-melt adhesive with double polyurethane gasket. Inside sponge can avoid any leakage. Injection molding mesh can protect the inside media very good.
* The pleated type can form a ventilation channel, increase filtration area and airflow, decrease the resistance.
* It is featured with high efficiency and dust holding, low resistance, uniform airflow, easy installation.
* It is individually tested via PSL particle, Using MPPS (DOP Test) laser particle counting device to measure overall efficiency of the filter.
* Temperature resistance: 80℃, relative humidity is 80%.
Application:
Mini-pleated HEPA filter is widely used as terminal filter in top grade purifying equipments of Electronics Factory, semiconductor, precision mechanism, pharmaceutical factory, hospital, food sanitation etc.
Hepa Filter,Coarse Pockets Filters,Pleat Hepa Filter,Paint Arrestor Filter,H14 HEPA Filter Guangzhou Airy Filter Media Co.,ltd , https://www.gzairy.com
The transformer DC resistance tester is an indispensable test item after the transformer is overhauled, overhauled, and changed on the tap changer. In the transformer transfer, overhaul, minor repairs, change the tap position, fault inspection and pre-test, etc., must measure the DC resistance of the transformer windings, its purpose is:
1. Check the welding quality of the internal wires and leads of the windings;
2. Check whether the tap switch is in good contact with each position;
3. Check the winding or lead wire for breakage;
4. Check the correctness of the parallel branch, if there is a single or several disconnection of the windings wound by several parallel wires;
5. Check whether there is any short-circuit between the layers and the turns.
product features:
1, lightweight, easy to carry, test speed.
2. Test current: 2.5A5A10A20A50A.
3, the use of imported high-quality components, software design multiple anti-interference program, the measurement accuracy is high, repeatability is good.
4, can store 255 test data, instrument reset, power down stored data are not lost, and can print all stored test data, easy to use.
5, liquid crystal display, adapt to a variety of different working environments.
Technical Parameters 
Transformer DC Resistance Tester Test Purpose
Transformer DC resistance tester adopts new power supply technology, which has the characteristics of rapid measurement, compact size, easy use and high measurement accuracy. It is an ideal device for measuring the DC resistance of transformer windings and high-power inductive devices. Transformer DC Resistance Tester