Dust Sampler Tamper-Proof Filter Cassette.

摘要

A new filter cassette is described that can be used with coal mine dust personal sampler units (CFR,Title 30,Part 74). The sealed cassette design reduces the chances of sample loss due to reverse flushing,impact,or cassette opening. The filter capsule weight is approximately 400milligrams and is stable for at least 1year in storage. The alpha-quartz content of the filter element is less than 5 nanograms per square millimeter of surface. The cassette is designed to be used with a new sampling head. The manufacturing costs of the new cassette will require an increase of approximately 30percent in the selling price.