US 6,284,545 B1 · Filter for gas sensor

Abstract

A filter for reducing the cross-sensitivity of a chlorine dioxide detector to hydrogen sulfide. The filter includes a high surface area substrate impregnated with a silver (I) salt or copper (II) salt which is effective to remove hydrogen sulfide from a gas stream without producing undesirable compounds which might be detected by the sensor. The preferred compounds are copper chloride (CuCl2), copper bromide (CuBr2), silver acetate (AgO2CCH3), silver bromate (AgBrO3), silver bromide (AgBr), silver carbonate (Ag2CO3), silver chloride (AgCl), silver chromate (Ag2CrO4), silver cyanide (AgCN), silver iodate (AgIO3), silver oxide (Ag2O), silver perchlorate (AgClO4), silver permanganate (AgMnO4), silver sulfate (Ag2SO4), silver hexafluorophosphate (AgPF6), silver fluoride (AgF), silver tetrafluoroborate (AgBF4), silver iodide (AgI) and silver trifluoromethane sulfonate (AgO3SCF3).

Claims13

Dependent claims

A method for specifically detecting chlorine dioxide in a gaseous medium comprising the steps of:

a) passing gaseous medium to be tested through a filter comprising a filter substrate impregnated with a solid reagent which is a silver I or copper II salt which reacts with hydrogen sulfide without producing an oxidizing or reducing gas, to thereby substantially remove hydrogen sulfide from the gaseous medium;
and
b) passing the gaseous medium from which hydrogen sulfide has been substantially removed to a means for specifically detecting chlorine dioxide, and detecting any chlorine dioxide present in the gaseous medium.

Dependencies are inferred from the claim text.

Filter for gas sensor

Life of this patent

Filter for gas sensor

Life of this patent

Abstract

Claims13