Abstract: A solid object carrying a catalyzer thereon is placed in a closed reaction chamber into which test gases are supplied and is heated up to a temperature of 1000.degree. C. Adsorbates are formed on the surface of the solid object under the test gas flow in the closed reaction chamber. Infrared radiations radiated from the adsorbates are emitted through an infrared-transmissive window hermetically formed on a wall of the closed reaction chamber, and are analyzed by an infrared radiation spectrometer and observed by a microscope. The infrared-transmissive window is cooled down by a cooling device attached thereto so that the temperature of the window does not exceed a certain level, e.g., 200.degree. C. Thus, the adsorbates formed on the solid object can be detected and analyzed under conditions where the test gas is actually flowing and the temperature of the solid object is elevated up to a high level.

Abstract: An infrared spectrometer disperses a radiation ray from a catalyst which has been exposed to a gas for evaluation to adsorb adsorbates thereon, and outputs spectral data in accordance with a wavenumber of the radiation ray to a computer storing reference data. The computer normalizes the spectral data and the reference data, and then, it calculates a product of the normalized spectral data and the reference data. Thereafter, a function of the product is differentiated with respect to the wavenumber to obtain a differential function. Accordingly, a specified wavenumber for which the differential function is zero is determined, so that the common peak of the spectral data and the reference data at the specified wavenumber is accurately determined.

Abstract: Anti-reducing semiconducting porcelain having a positive temperature coefficient of resistance comprises a barium titanate composition, and a flux containing 0.14 to 2.88 parts by weight of TiO.sub.2 0.1 to 1.6 parts by weight of Al.sub.2 O.sub.3 and 0.1 to 1.6 parts by weight of SiO.sub.2 per 100 parts by weight of the barium titanate composition. It has a high positive temperature coefficient of resistance which does not show any appreciable change in the presence of a reducing atmosphere, such as hydrogen gas or gasified gasoline. It need not be isolated from a reducing atmosphere by a plastic or metallic enclosure, but can be exposed thereto. The flux may further contain a zinc, potassium or lithium compound.

Abstract: A positive ceramic semiconductor device having positive temperature coefficient of resistance comprises a pair of electrodes provided on a ceramic semiconductor substrate. One of the paired electrodes which is to serve as the positive pole is basically constituted by at least an electrically conductive layer of silver-palladium series containing silver and palladium at a predetermined ratio. For preventing a localized current concentration from occurring in the current conducting state, improvement is made as the structure of the positive pole electrode ormed of the electrically conductive material of silver-palladium series and/or the structure of the negative pole electrode. Silver-migration phenomenon on the positive ceramic semiconductor substrate as well as degradation of the mechanical strength thereof is positively prevented.