摘要:
A breath alcohol-measuring device for breathing gas sampling has a mouthpiece (2), for receiving the exhaled breathing air (1) of a test subject, provided with a first flow diaphragm (3). A first pressure sensor (6) is connected to the mouthpiece via a first gas line upstream of the flow diaphragm (3). An alcohol sensor (4) is connected to the mouthpiece (2) via an inlet channel downstream of the flow diaphragm (3) and to a sampling system (5) for a breathing gas sample from the breathing air (1) via a second gas line. The second gas line between the alcohol sensor (4) and the sampling system (5) has a second flow restriction (diaphragm 7) and is connected to a second pressure sensor (9). An evaluating and control unit (8) receives the measured signals of the pressure sensors (6, 9) and of the alcohol sensor (4) and actuates the sampling system (5). The sampling system (5) includes a bellows (10) with a piezo drive (30) and is actuated by the evaluating and control unit (8) as a function of the volume measured by means of the second pressure sensor (9).
摘要:
A breath alcohol measuring device includes a flow chamber, for receiving exhaled breathing gas of a person, with a flow diaphragm. A differential pressure sensor has a first measuring connection via a first gas line (5) to the interior space of the flow chamber (2) upstream of the flow diaphragm (3), and a second measuring connection via second and third gas lines (12, 15) and a breath alcohol sensor (8) to the interior space of the flow chamber (2) downstream of the flow diaphragm (3). A throttling element (14) is present in the second gas line (12). The second gas line (12) is connected to a sampling system (9, 10), and an evaluating and control unit (6) is connected to the sensors (4, 8) and to the sampling system (9, 10) for controlling the sampling system.
摘要:
A device for calibrating a gas meter, in which gas to be analyzed is introduced into a measuring chamber by a delivery device via a delivery line. A storage tank is provided containing a calibrating substance, which tank is connected to the measuring chamber via a feed line. The storage tank is designed as a tank through which the gas to be analyzed can flow and has a gas inlet. A flow divider is provided in the course of the delivery line. A partial flow of the gas to be analyzed is sent by the flow divider to the gas inlet via a section of the feed line. The gas meter is an electrochemical measuring cell determining a measured concentration value of the calibrating substance in the gas to be analyzed in the measuring chamber. An infrared meter is provided, which evaluates the gas to be analyzed in the measuring chamber and generates a reference measured concentration value for the measured concentration value determined with the electrochemical measuring cell.
摘要:
A gas measuring and warning device includes a test tube which is traversed by the gas to be detected and with a photoelectric sampling means which contains an imaging optical system by which the test tube reaction image is projected onto the photo-sensitive row of the sensor elements. The imaging optical system contains a cylindrical lens having a cylinder axis which is parallel to the longitudinal axis of the test tube and to a row of sensor elements. Advantageously an achromatic lens as well as of an interference filter and of a pulse light source as used.
摘要:
A device for optical detection of a target gas in gas mixtures includes an operation and evaluation unit, a measurement cuvette with optically reflective surfaces on its interior walls and a gas inlet to the environment, a radiation source, a measuring detector and a reference detector unit provided on the measurement cuvette. The measuring detector and the reference detector unit detect the light of the radiation source and produce electrical signals corresponding to the intensity of the detected light. An optical bandpass filter element, constructed to transmit light of a measurement wavelength, is arranged upstream of the measuring detector. An optical double-bandpass filter unit, that transmits light of a first reference wavelength and light of a second reference wavelength, is arranged upstream of the reference detector unit. The operation and evaluation unit operates the radiation source and acquires the electrical signals of the measurement detector and the reference detector unit.
摘要:
A gas concentration-measuring device makes it possible to measure gas components in a gas sample. An interferometer, based on a dual-band Fabry-Perot interferometer (1), is provided with a transmission spectrum that can be set by a control voltage (38). The control voltage (38) of the dual-band Fabry-Perot interferometer (1) is synchronized over the course of time with the activation and deactivation of the radiation sources (11, 12).
摘要:
The invention is directed to a measuring method for determining the concentration of a gas in a measurement sample with the aid of a combined measuring apparatus. The measuring apparatus includes a first infrared optical gas analyzer 1 as well as a second gas analyzer 2, which contains an electrochemical measuring cell 13. The measuring result of the electrochemical measuring cell 13 functions to correct the concentration, which is determined by the infrared optical gas analyzer 1, when the infrared optical reference measurement has already been performed on a measurement sample with this measuring sample not being free of the substance to be detected.
摘要:
The invention relates to a method for quantitatively determining a gas component of a gas flow and an apparatus therefor. The apparatus includes a testing conduit having a throttle through which the gas flow flows. A sample conduit leading to the gas inlet of a gas sensor branches away from the testing conduit upstream of the throttle. The apparatus further includes a pressure sensor connected to the sample conduit, a valve connected to a gas outlet of the gas sensor and a control unit. The method of the invention is improved in that a defined quantity of gas can be supplied to the sensor without a pump being required. An improvement is achieved in that the control unit is so configured that: in a first step, the valve is opened; the gas volume is determined in a second step by computing the time integral of the signal of the pressure sensor; and, in a third step, the valve is closed after the throughflow of a pregiven gas volume or after a pregiven time duration has elapsed.
摘要:
A device for the transport of a gas sample into the measuring chamber of a detector for the determination of the portion of a component in a gas, and in particular of alcohol in respiratory air, includes a piston-cylinder unit serves as the transport element. The sample is used as completely as possible for the signal analysis of the sensor at the beginning of the sampling process. The measuring-sensitive surface of the sensor comprises a part of the wall of the cylinder chamber of the transport unit which serves as the measuring chamber. The path on which the sample is guided between the inlet and the cylinder chamber is defined by a deviation baffle provided along the measuring-sensitive surface of the sensor.
摘要:
A process is provided for verifying an electrochemical substance in a gas sample. The process generates in an electrochemical sensor a measured electric value changing over time with a characteristic rising from a reference line to a maximum and again declining to the reference line. The percentage of the electrochemical substance in the gas sample is determined in an analysis circuit by setting a first interval and a second interval in the range of the characteristic after the maximum has been exceeded. The first interval includes the range of the characteristic in the vicinity of the maximum and the second interval includes the range of the maximum in the vicinity of the reference line. The electrochemical substance is determined by determining the ratio of the slopes of the first and second intervals and by comparison with a reference value of the ratio of the slopes of the first and second intervals.