04272479 is referenced by 19 patents and cites 3 patents.

A method of testing air for measuring the chromate and chromic acid aerosols therein, comprises, passing the air through a testing tube after each end of the tube has been broken to cause the particles in the air to become entrained on a filter in the tube and, thereafter, breaking an ampoule of sulfuric acid in the tube so that it flows through the filter and dissolves the entrained particles and brings them into contact with a filling material which is also arranged in the tube and which produces a reaction with the particles of chromate and chromic acid which are deposited on the filter. The reaction produces a violet dye, the intensity of the discoloration being directly proportional to the mass of the deposited chromate or chromic acid. The testing tube comprises a closed testing tube having breakoff ends at each end with holders for positioning an ampoule of sulfuric acid upstream in respect to the direction of testing air flowing through the tube of a filling material which includes a granular reagent layer of an earth quartz and diphenyl carbazide, together with a sorption-active silica gel and a subsequent layer of granular quartz.

Title
Testing tube for measuring chromate and chromic acid aerosols in air
Application Number
6/125979
Publication Number
4272479
Application Date
February 29, 1980
Publication Date
June 9, 1981
Inventor
Wilfried Laufenberg
Lubeck
DE
Karl Heinz Huneke
Lubeck
DE
Agent
McGlew and Tuttle
Assignee
Dragerwerk Aktiengesellschaft
DE
IPC
G01N 27/62
B63H 1/00
F01B 23/00
View Original Source