摘要:
A hydrogen sensor 25 has a fitting base plate 29 in which a gas-sensing chamber 34 is formed, a specimen gas intake 35 formed on said fitting base plate 29, opening toward an exit passage 24 and introducing hydrogen gas into the gas-sensing chamber 34, a gas-sensing element 39 held in the gas-sensing chamber 34 and adapted to sense hydrogen gas, and a water-repelling filter 44 covering the specimen gas intake 35.
摘要:
A gas sensor (1) has a pressure-tight sensor housing (4). The sensor housing (4) has a metal plate (5) at its lower end and the metal plate (5) has breakthroughs (6, 7, 8). Metal pins (9, 10, 11) electrically contact the sensor elements (2, 3) and these metal pins are brought to the outside via glass inserts (15, 16, 17).
摘要:
A gas sensor is provided that is delimited from the environment with a preferably replaceable cap (8) made of a porous, gas-permeable and water-impermeable material, especially sintered PTFE. The gas sensor is protected against environmental moisture and can be permanently provided with the cap (8) and with a special calibrating adapter (9) both during the gas measurement and during the necessary calibration. Due to the special design of the cap (8) and the calibrating adapter (9), the gas sensor offers the possibility of remote calibration, which can be carried out with high accuracy and is independent from weather effects, especially wind.
摘要:
New sensors and methods for qualitative and quantitative analysis of multiple gaseous substances simultaneously with both high selectivity and high sensitivity are provided. The new sensors rely on a characteristic difference in energy between the interaction of a particular substance with a catalyst coated heat transfer device (HTD) and a non-catalyst coated (or one coated with a different catalyst) reference HTD. Molecular detection is achieved by an exothermic or endothermic chemical or physical reaction between the catalytic surface of the sensor and the molecule, tending to induce a temperature change of the sensor. Both high temperature and non-destructive low temperature detection are possible. The magnitude and rate of endothermic or exothermic heat transfer from a specific molecule-catalyst interaction is related to molecular concentration.
摘要:
A process is provided for measuring a gas concentration with at least one thermal measuring element. The thermal measuring element is operated by pulses. A measured value of the gas concentration in the environment of the measuring element is obtained from the evaluation of the response of the measuring element to at least one single pulse by determining transient states of the thermal measuring element. From this the measured value of the gas concentration in the environment of the measuring element can be derived, during the imposed pulse based on electric measured variables.
摘要:
A lead portion (25) of a heater coil (22) is constituted of a single coil wound into a coil and a bead portion (24) is constituted of a double coil formed by further winding the single coil into a coil. By constituting a detecting element (2) by burying the bead portion (24) in a heat conductive layer (21) and adhering a catalyst layer (23) on the surface of the heat conductive layer (21), improvement of the gas sensitivity and the response speed of a catalytic combustion gas sensor is facilitated. Zero point variation is reduced by improving impact resistance. When both ends of the heater coil are fixed to electrode pins, both ends of the heater coil are welded to the electrode pins using a resistance welding method, etc., with a platinum wire, etc., wound on a primary core wire, and thereafter, the primary core wire is melted and eliminated while leaving the platinum wire, etc., by a wet etching process.
摘要:
A control device determines whether or not the detected value of a unit conducting current output from a current sensor at least plural times is equal to or greater than a predetermined upper limit current at time of the start of the actuation of a gas sensor, and furthermore, determines that each of the units of the gas sensor is set in an abnormal state if a duration for a state in which it is determined that the detected value of the unit conducting current is equal to or greater than the predetermined upper limit current is equal to or longer than a predetermined upper limit time. On the other hand, if the duration for the state in which it is determined that the detected value of the unit conducting current is equal to or greater than the predetermined upper limit current is shorter than the predetermined upper limit time, it is determined that the detected value of the unit conducting current temporarily becomes equal to or greater than the predetermined upper limit current and each of the units is set in a normal state.
摘要:
A contact combustion-type gas sensor that can maintain its initial sensitivity over a long period of time in the presence of silicon vapor, wherein an induction portion 5 of a gas detecting element 1 contains not less than 30 percent by weight of an oxidation catalyst, and is aged in advance in an environment that contains silicon vapor serving as a poisoning substance.
摘要:
A poison resistant combustible gas sensing element, a method for its production and a method for determining poisoning of the element. The element includes an electric heating element, an inner layer coated on the electric heating element and containing a precious metal catalyst supported on a porous oxide, the precious metal catalyst catalyzing combustion of a combustible gas to be detected by the element, and an outer layer overlaying the first layer, and containing a catalytic compound capable of trapping gases which poison the precious metal catalyst, the catalytic compound being supported on a porous oxide.
摘要:
A degradation diagnosis method for simply performing degradation diagnosis of a gas sensor such as a hydrogen sensor. The hydrogen sensor has a reference detector member and common detector member, with each detector member respectively constituted of a detector element and temperature compensating element that form a pair. Power is normally supplied to the common detector member, which performs concentration detection of the hydrogen gas. When performing degradation diagnosis of this common detector member, concentration detection is performed simultaneously by each detector member for the gas of the prescribed hydrogen concentration by supplying power to both the common detector member and reference detector member and comparing the output value of the common detector member and the output value of the reference detector member.