Abstract: The measuring apparatus is based on an electrochemical sensor with a hollow chamber connected upstream through which the gas to be measured diffuses to the sensor surface. A pump for introducing a rinsing gas is connected to the hollow chamber. Moreover, the rinsing gas connection is connected to a test gas source which produces a known concentration of the component to be measured. The function of the sensor may be controlled by connecting the test gas source. The accuracy of the measured values and thus the reliability of the measuring apparatus may be substantially improved by these measures.

Abstract: A method for monitoring the exposure of an individual person to toxic gases is carried out such that the gas concentration is continuously measured with a sensor for the specific gas, recorded and the measured values then read and evaluated. Instantaneous values of the concentration are periodically scanned, temporal mean values of the instanteous values are formed over a predetermined time interval, these mean values are stored and an alarm triggered if the instantaneous value and/or the mean value exceeds a predetermined critical value over the time interval or an integral multiple thereof.

Abstract: Plaques for rapid retrospective recognition of an overdose of noxious gases are of great importance for industrial protection in the chemical industry. These plaques carry an indicator which undergoes a color change on exposure to the gas. Visual assessment of the indicator is considerably facilitated by subdivision of the indicator surface into a plurality of measuring fields with graded sensitivity by means of different covering membranes. Rapid allocation to a given range of dose is possible by separate or combined visual observation of the individual fields of the indicator.

Abstract: An apparatus for checking gas analysis devices in respect of their sensitivity and their response and regeneration behaviour with respect to time, wherein a reproducible quantity of the measurement component is produced at a predetermined production rate, for a period of time which is guided entirely or at a constant proportion as a concentration pulse to the measurement element of the gas analysis device. For the production of the measurement component a chemical or electro-chemical reaction or even a thermal reaction is used. The time interval can then be conveniently controlled. A decisive advantage with toxic measurement components is that the gas production takes place in all cases for only a short time during the test procedure.

Abstract: A method for checking gas analysis devices in respect of their sensitivity and their response and regeneration behaviour with respect to time, wherein a reproducible quantity of the measurement component is produced at a predetermined production rate, for a period of time which is guided entirely or at a constant proportion as a concentration pulse to the measurement element of the gas analysis device. For the production of the measurement component a chemical or electro-chemical reaction or even a thermal reaction is used. The time interval can then be conveniently controlled. A decisive advantage with toxic measurement components is that the gas production takes place in all cases for only a short time during the test procedure.

Abstract: An electrochemical gas detector based on an electrolytic measurement cell having a normally solid organic electrolyte. The gas component to be detected diffuses out of the gas chamber at a three phase border (electrolyte-electrode-gas chamber) and there causes a change in the electrochemical equilibrium. As a result in an outer closing circuit a measurable electrical current is produced. The electrolyte consists of an anhydrous organic gel with a very low vapor pressure. The gas chamber adjacent to the three phase border constitutes a partly sealed cavity, which is in communication with the gas atmosphere to be examined via an absorption filter selectively permeable to the measurement component. The length of the cavity is dimensioned so as to be so short that practically no back diffusion of the measurement component through the filter takes place.