Abstract: A push button for a vending machine. The push button includes a lens that is depressed by the customer. Under the lens is a transparent or semi-transparent flexible cover over a plurality of light emitting diodes (LEDs). The color and arrangement of the LEDs can be varied to provide a number of different indicating modes. The present invention does not require items in conventional push buttons, for example, a letter and symbol plate or a reflector case.

Abstract: When adsorbed gas is analyzed after metal, ceramics or metallic salt has been left in an environmental atmosphere for a predetermined period of time, an average concentration of specific gas over a long period of time can be accurately measured with an inexpensive small apparatus. Especially, porous metal or ceramics (transition metal oxide) are excellent in selective adsorption properties for NO.sub.x, porous ceramics (rare earth element oxide) are excellent in selective adsorption properties for CO.sub.2, and a specific chloride such as copper chloride and silver chloride is excellent in selective adsorption properties for SO.sub.2. A test kit accommodating such test pieces in a case, a protective case for the test kit to put the test kit into practical use, an umbrella and a forced air blowing unit are also disclosed.

Abstract: When adsorbed gas is analyzed after metal, ceramics or metallic salt has been left in an environmental atmosphere for a predetermined period of time, an average concentration of specific gas over a long period of time can be accurately measured with an inexpensive small apparatus. Especially, porous metal or ceramics (transition metal oxide) are excellent in selective adsorption properties for NO.sub.x, porous ceramics (rare earth element oxide) are excellent in selective adsorption properties for CO.sub.2, and a specific chloride such as copper chloride and silver chloride is excellent in selective adsorption properties for SO.sub.2. A test kit accommodating such test pieces in a case, a protective case for the test kit to put the test kit into practical use, an umbrella and a forced air blowing unit are also disclosed.

Abstract: There is provided a test piece by which NO.sub.x, present in an environment may be visually observed apart from the influence of other gases, and with which qualitative and quantitative analysis may be performed. The test piece has a layered structure prepared by vacuum deposition a metal thin-film (Ag, Pt, Au, etc.) on a metal substrate (Cu, Zn, etc.). The rough amounts of NO.sub.x, SO.sub.x and NH.sub.3 in the environment are determined on the basis of the corrosion products (nitrates, etc.) produced when NO.sub.x, SO.sub.x and NH.sub.3 are collected after the test piece has been exposed to the environment for a prescribed period of time.