Dispersed Oil Particulate (DOP) Testing of Filter Systems


Micronair Engineering have recently introduced an innovative method of testing dust extractor installations.

Originally intended for the production testing of Absolute (HEPA) filters, this test - generally referred to as a DOP (Di-Octyl Phthalate) test, introduces an exceedingly dense cloud of sub-micronic particulate into the dirty side of the filter under test.

(Because of concern that Di-Octyl Phthalate may have carcinogenic properties, it has been replaced by an alternative product, although the abbreviated name has been retained - now signifying Dispersed Oil Particulate.)

The clean side is then viewed against a (preferably) dark background, where the slightest seepage of smoke can be clearly observed, so that even the most minute leakage can be dealt with.

Micronair Engineering have improved the technique by utilising a portable laser to enhance the visual characteristics of the smoke.

Whereas the UV test requires the system to be under power for a brief period, this test relies entirely upon the very searching nature of the particulate to identify the smallest possible leaks.

It is particularly suited to the testing of the recently introduced ceramic fibre candle filters, and in applications where the introduction of an opaque and brightly coloured dye (the UV Fluorescent Test) would be inconvenient or undesirable.

The base product used in the test is totally safe with regard to ingestion or inhalation in use, and it is highly improbable that contamination of the product would occur. Prior confirmation should be sought if there is cause for doubt.

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