Abstract: A sensor material for gases or vapors including solvent vapors, comprising at least one hydrophobic metal complex with an ion mobility or ionic concentration or optical properties, which change under the effect of the gas or vapor. These metal complexes can be applied to suitable electrode arrangements or carriers and, in conjunction with simple measuring bridges or photometers, form a sensor system for gases and vapors.

Abstract: An apparatus comprising a chemically sensitive sensor material, having an electrical resistance or dielectric constant which changes under the effect of the gases or vapors. According to the invention, this sensor material, which comprises either hydrophobic metal complexes, or a mixture of at least one phthalide and at least one acidic compound, serves as resistance or as dielectric material. These sensor materials change their ion mobility and/or their ionic concentration under the effect of gases or vapors, thereby changing their resistance or capacitance. The change in resistance or the change in capacitance can expediently be converted into a frequency change by a multivibrator. Thus, one obtains an especially simple and very effective sensor for gases and vapors.

Abstract: An apparatus comprising a chemically sensitive sensor material, having an electrical resistance or dielectric constant which changes under the effect of the gases or vapors. According to the invention, this sensor material, which comprises either hydrophobic metal complexes, or a mixture of at least one phthalide and at least one acidic compound, serves as resistance or as dielectric material. These sensor materials change their ion mobility and/or their ionic concentration under the effect of gases or vapors, thereby changing their resistance or capacitance. The change in resistance or the change in capacitance can expediently be converted into a frequency change by a multivibrator. Thus, one obtains an especially simple and very effective sensor for gases and vapors.

Abstract: The disclosed method relates to a method for recording flow boundary layers in liquid media by photochemical means. According to the invention, surfaces which can be developed in a plane and to which a photographic film sheet is cemented are exposed under steady-state conditions to the flow of a liquid medium containing a dissolved agent reacting with the photo gelatin layer. The liquid medium may contain agents furnishing HS-ions or agents capable of dissolving silver halide or reducing silver halide. If a photographic film sheet is used, the silver ions of which are reduced to silver, the flow exposure is performed with an agent having oxidizing and dissolving action. With the method disclosed, half-tone photograms of flow boundary layers in liquids can be recorded.

Abstract: The invention relates to a method for making visible by photochemical means residual moisture distributions in photographic wet film layers subjected to a gas flow. According to the invention, a film diffusely pre-exposed is immersed in an aqueous swelling agent solution which contains either (a) a reducing agent or (b) an alkali. After being exposed to the air stream, the invisible residual moisture profile is immersed in an alcoholic solution of either (a) an alkali or (b) a reducing agent. The half-tone image produced serves for determining stationary local boundary layer thickness distributions, wall shearing stresses, material transfer coefficients and heat transfer coefficients.