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Dräger sampling tubes and systems - 20351 A

2.Dräger-Tubes and Applications2.1Dräger-Tube Measurement

Today, detector tubes are one of the classical measurement techniques of gas analysis. The first detector tube patent appeared in America in 1919. Two Americans, A. B. Lamb and C. R. Hoover, impregnated pumice with a mixture of iodine pentoxide and sulfuric acid. This preparation, which they put in a vial, became the first chemical sensor for measuring or rather detecting carbon monoxide. Before this early detector tube, canaries were used as “sensors” in coal mining.This first detector tube was only used for qualitative detection of the presence of carbon monoxide, quantitative measurement was not yet possible. Today the Dräger-Tubes provide quantitative results with a highdegree of accuracy and selectivity. Since the development of the first Dräger-Tube, more than 70 years ago, Drägerhas expanded the product line and Dräger-Tubes belong to the traditional products of Dräger.In comparison with the firstdetector tube patent, the basic shape and structure of a tube may appear not to have changed;however, closer inspectionreveals the contents havechanged dramatically. What is aDräger-Tube? Simplistically, it isa vial which contains a chemicalpreparation that reacts with themeasured substance by chang-ing color. To achieve the normal shelf life of 2 years the tube tips are fused at both ends.Thus, the vial provides an inert package for the reagent system. Most of the Dräger-Tubesare scale tubes and it should be emphasized that the length-of-stain discoloration is an indication of the concentration of the measured substance.