Prüfmethoden für Luftfilter

Test types

We distinguish between the type test and the test in the manufacturing plant.

The type test of the filter is carried out by the standard procedure corresponding the given filter (see charter no 2). The tested filter should represent a set construction series. This condition is met provided the tested item is identical with the construction series in the following characteristics: the type description (1), the depth of the "filter complex" in the direction of the airflow, and the speed of the airflow through the filter medium. Other characteristics of the tested item can differ, e.g. the size, the shape of the reaction area. The type tests can be performed by all testing places accredited according to EN 45000. The class is allotted based on the valid attestation by some of the accredited testing places, which must include an explicit description of the tested product, the testing conditions and the test results. The type tests are important for coarse and mainly for the fine dust filters.

The test in the manufacturing plant
It applies to filters, which do not have the type tests, or to filters, which are, in accordance with the valid standards, subject to the respective test (e.g. the filters HEPA and ULPA). The classification of the filter can be done on the base of the tests in the manufacturing plant providing the manufacturer's testing equipment conforms to the valid standards, the test is carried out according to valid standards and the manufacturer has the quality assurance system in accordance with ISO 9000.

The tests in the manufacturing plant are performed using the manufacturer's testing equipment. The ground for the classification is the trial attestation, which includes an explicit description of the tested product, the testing conditions and the test results. The recognition of these tests is within the competence and responsibility of the buyer.

The testing procedure and classification of the air filters

Classification of the air filters into "categories" and "classes" (charter no 2) is done on the base of the results of the separation capacity measurements accomplished by the procedure described herein below. Detailed and binding information is provided by the respective standards.

Category G: Filters for coarse dust
Classes G1-G4

Category F: Filters for fine dust
Classes F5-F9

Category H: HEPA filters for micro-particles
Classes E10-E12, H13-H14

For the filter classification the limit values of integral and topical penetration factors of the respective classes must not be exceeded.