GB1032177A - Alcohol indicator - Google Patents

Abstract

1,032,177. Breath analysers. LUCKEY LABORATORIES, Inc. Aug. 1, 1963, No. 30547/63. Heading A5R. [Also in Division G1] An apparatus for visual determination of the alcohol content of human alveolar breath comprises a transparent, e.g. glass or plastic, indicator 14 having open ends for ingress and egress of alveolar breath, and an alcohol sensitive indicator 16 secured inside the tube 14 and which is subject to progressive colour change in response to alcohol in the alveolar breath passing through the indicator tube 14, the indicator comprising silica gel impregnated with a mixture of concentrated sulphuric acid, distilled water and a chromate ion producing substance (e.g. sodium and ammonium dichromate) having water solubility characteristics at least great enough so that the weight of the quantity of water required to dissolve the substance is less than the weight of the substance to be dissolved therein. The indicator may be divided into portions 16A, 16B by glass grit 17 and held in tube 14 by packing material 18 and retaining members 19, 20. The tube may have marking means 21 to indicate the alcohol content present in the breath Stoppers may be inserted in the tube when not in use, silica gel being placed between the stoppers and the retainer members. The apparatus may include balloon 11 and mouth piece 12. The balloon 11 may be placed intermediate the tube 14 and mouth piece 12, valve 13 being provided to prevent air flowing from balloon 11 through mouth piece 12 or may be placed at end of tube 14, the mouth piece 12 being placed at the other end. The balloon exerts a pressure on the breath contained therein. The rate of flow of the alveolar breath may be controlled by the contents of the tube 14 or by a metering orifice in the tube 14.