Abstract: In connection with an electrode holder for immersion-type flow-type and attachment-type measuring systems in analytical chemistry, in particular for pH, conductivity, oxygen and chloride measurements, or the like, comprising an outer pipe in which an inner pipe carrying the measuring probe is supported in axially sliding relationship, and a stopcock blocking the supply of measuring agent by means of a plug of the stopcock when the inner pipe is retracted from the measuring agent it is proposed to leave the plug open on one side in the area of its passage channel and to have a remaining rear wall of the passage channel facing the supply opening of the measuring agent.

Abstract: In a gas detection system for detecting the content of inflammable, explosive and/or toxic or other gases an arrangement is proposed according to which a central electronic evaluation system is connected to a plurality of measuring heads, which are installed at the points of measurement, by a single common two-wire line and each measuring head is provided, at its place of installation, with its own intelligence (microprocessor) for processing at least partly the values supplied by the sensor, each measuring head being equipped with at least two sensors of different types or measuring ranges and with an additional temperature sensor and each sensor having an identification which is indicative of the type and measuring range of the sensor and which is picked up by the measuring head.

Abstract: In connection with a method and a device for processing measured values, where resistance variations are evaluated as a measure for the variation of the gas concentration to be measured, it is proposed to measure a basic resistance value at least once, preferably repeatedly, by admitting a standard calibration gas, and to store this resistance value and derive therefrom, for each subsequent measurement of the gas component the concentration of which is to be measured, by an arithmetic operation, the ratio between the resulting total resistance value and the momentary basic resistance value, and to evaluate the ratio so obtained for further processing.