Browse Prior Art Database

Prefilter for the H(2)S Tape Sampler

IP.com Disclosure Number: IPCOM000073760D
Original Publication Date: 1971-Jan-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 1 page(s) / 12K

Publishing Venue

IBM

Related People

Cappell, RJ: AUTHOR

Abstract

Hydrogen sulfide (H(2)S) gas at concentration levels as low as 1 part per billion (ppb) can be harmful to electronic equipment, and a reliable means of measuring the gas at these concentrations is required. All known methods, including the convenient lead acetate tape sampler, are subject to serious interference from other pollutant gases. A benzidine cartridge prefilter was developed to remove interfering gases and particulates, and to permit continuous unattended operation of the H(2)S tape sampler for one week periods.

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Prefilter for the H(2)S Tape Sampler

Hydrogen sulfide (H(2)S) gas at concentration levels as low as 1 part per billion (ppb) can be harmful to electronic equipment, and a reliable means of measuring the gas at these concentrations is required. All known methods, including the convenient lead acetate tape sampler, are subject to serious interference from other pollutant gases. A benzidine cartridge prefilter was developed to remove interfering gases and particulates, and to permit continuous unattended operation of the H(2)S tape sampler for one week periods.

The cartridge prefilter, which was designed to fit directly on the air intake of a commercial H S tape sampler (Gelman Instrument Co.) , was constructed in the following manner:

A commercially available plastic dust filter cartridge (Millipore Catalog No. MAWGO37AO) served as the prefilter case. The cartridge, complete with its 0.8 micron Millipore filter, was tightly packed with benzidine treated firebrick, described below. A dust filter cut from high efficiency filter material (Mine Safety Appliances Co. , Cat. No. M-75428) was fitted into the top portion of the plastic cartridge and held in place with a slightly oversized 0 ring. The cartridge was then assembled and taped to prevent air leakage.

The critical portion of the cartridge prefilter consists of the bed of benzidine treated firebrick particles. Any efficient filter media can be substituted for the dust filters - provided it does not adsorb H(2)S o...