1168529-A is referenced by 3 patents.
1,168,529. Gas analysis. LUCKEY LABORATORIES Inc. Nov.7, 1967, No. 50457/67. Heading G1B. Apparatus for determining alcohol in human breath comprises a first inflatable and expansible container e.g. a balloon 26 which can be expanded to a selected size by a person blowing through a mouthpiece 28 through a check valve 29, a tube 10 containing a reagent which changes colour in the presence of alcohol vapour connected to the outlet of the balloon 26 and leading to a second inflatable but non-expansible container e.g.; a polyethylene bay 27 which has a predetermined inflated capacity, the arrangement being such that when the balloon is inflated it exerts a selected pressure on the breath therein, and material in the tube is packed so that it defines a selected impedance to gas flow therethrough these two features co-operating to provide a predetermined rate of flow of breath through the tube 10. The colour change reagent is preferably a mixture of a chromate ion producing substance and sulphuric acid on silica gel and this is disposed in layers between layers of inert material e.g. glass grit. In use the balloon 26 is inflated by the person under test with its outlet closed by pinching or twisting. When it has been inflated to the selected size the outlet is opened and the breath passes through the tube 10 to fully inflate the bag 27.; In place of the balloon 26 an ordinary balloon may be used and this is connected to the tube 10 after inflation. Also, the mouthpiece 28 may be formed as a T-piece with an extra inflatable but non- expansible bag connected to the arm of the T. In this case the balloon will not be inflated until this extra bag is full and the volume of this bag is arranged to be approximately that of a human mouth and bronchial tract. Further, if desired, a tube containing an alcohol absorbent e.g. magnesium perchlorate may be substituted for the tube 10, alcohol absorbed thereon being subsequently analysed in a laboratory.