The classification of aeriform sensor

National level GB7665-87, it is to the definition of sensor: Sensor is the parts of an apparatus that can experience a regulation to be measured and becomes usable output signal according to definite pattern changeover or device. Aeriform sensor is to be used detect the sensor of aeriform component and content, think commonly, with detecting the target is classified foundation the definition of aeriform sensor, that is to say, always use at detecting aeriform component and pH indicator sensor call gas sensor, no matter it is to use physical method, still be chemically method. For instance, detect the sensor of aeriform discharge is not regarded aeriform sensor, but analyzer of gas of thermal conductivity type belongs to important aeriform sensor however, although they use cardinal principle sometimes,detect consistently principle. Be in early last centuries 70 time, aeriform sensor has made a of sensor domain large department, belong to a branch of chemical sensor. At present popularity is like below a few sort about at the aeriform sensor of the market: 1, sensor of semiconductor type gas it is to use data of semiconductor of oxide of a few metals, below constant temperature, electrical conductivity makes as the change and changes principle of environmental gas component. For instance, alcohol sensor, when using 2 oxidation stannum to encounter alcohol gas below high temperature namely, of the principle preparation that resistor can reduce quickly. Sensor of semiconductor type gas uses effectively at: The ground of a lot of gas such as methane, ethane, propane, butane, alcohol, formaldehyde, carbon monoxide, carbon dioxide, ethylene, acetylene, chloric ethylene, styrene, acrylic acid detects. Especially, cost of this kind of sensor is low, the demand that detects at civil gas aptly. Following sensor of gas of a few kinds of semiconductor type is a success: Methane (natural gas, firedamp) , alcohol, carbon monoxide (the city is gas) , vulcanization hydrogen, ammonia is angry (include amine, hydrazine kind) . The sensor of high quality can satisfy the need that industry detects. Defect: Stability is poorer, suffer an environment the impact is bigger; Especially, of sensor of avery kind of not be exclusive optionally, output parameter also cannot decide. Accordingly, unfavorable at the place of metric and accurate requirement applying. At present the main supplier of this kind of sensor is in Japan (contriver) , it is China next, have recently new joined Korea, other country also has the job that comparative in this respect like the United States, but did not collect the mainstream from beginning to end! The manpower that China throws in this domain and time no less than Japan, but because come for years,national policy directs and social news is out-of-the-way wait for a reason, our country is popular the Dou Yuanxun of quality of performance of sensor of semiconductor type gas at the market at Japanese product, believe, progress as the market, of civilian battalion capital farther arisen, the sensor of semiconductor type gas that China produces is achieved and surpass Japanese level already can be expected soon! 2, sensor of gas of catalytic combustion type this kind of sensor is the activator layer with the exterior high temperature resistant preparation in platinic resistor, below constant temperature, flammability gas is in its surface catalytic combustion, combustion is platinic resistor temperature lifts, resistor changes, metabolic value is function of flammability gas pH indicator. Sensor of gas of catalytic combustion type detects optionally flammability gas: Always can flaming, can detect; Always cannot flaming, sensor does not have any response. Of course, "Always can flaming, can detect " this one has a lot of exception, but, will always tell, afore-mentioned hold water optionally. Sensor of gas of catalytic combustion type is metric and accurate, answer fast, life is longer. The explosive danger of the output of sensor and environment is direct and relevant, the sensor that the domain is position of a kind of dominant is measured in safe check. Defect: Inside flammability gas limits, without alternative. Dark anger works, have the risk that ignition explodes. Major element organic vapour has toxic effect to sensor. At present the main supplier of this kind of sensor is in China, Japan, England (invention country) ! The biggest user that at present China is this kind of sensor (colliery) , also have first-rate sensor to manufacture a technology, although ceaselessly various agents disturb a society to be opposite on conduct propaganda,this is planted the understanding of sensor, but after all, the mainstream manufacturer of sensor of gas of catalytic combustion type is in home. 3, gas of avery kind of of sensor of gas of type of thermal conductivity pool, have oneself specific thermal conductance, mix when two when the thermal conductance difference of many gas is bigger, can use thermal conductivity cell, differentiate among them the content of a constituent. This kind of sensor already used what Yu Qing enrages to detect via sensor ground, of carbon dioxide detect, of high concentration firedamp detect. Range of applicable of sensor of this kind of gas is narrower, limitative element is more. This is a kind of vintage product, whole world each district has manufacturer. Product quality whole world very much the same. 4, sensor of electrochemistry type gas comparatives of the combustibility of one part, poisonous and harmful gas has electrochemistry active, can be oxidized by electrochemistry or reductive. Use these response, can differentiate aeriform component, detect aeriform chroma. Electrochemistry gas sensor divides a lot of subclass: (1) , sensor of galvanic cell gas (also say: Add sensor of Fu Ni batteries gas, also have call fuel cell gas sensor, also have call galvanic cell gas sensor) , their principle is the same as the dry cell that we use all right, just, the carbolic manganese electrode of batteries was replaced by aeriform electrode. It is with aerobic sensor exemple, oxygen is in cathode by reductive, the electron sheds positive pole through ammeter, over plumbic metal is oxidized. The chroma of voltaic size and oxygen is direct and relevant. This kind of sensor detects effectively sulfur of oxygen, 2 oxidation, chlorine. (2) , constant potential electroanalysises pool gas sensor, this kind of sensor is used at detecting reducing gas is very effective, its principle and galvanic cell sensor is different, its electrochemistry reaction is in next electric current is compulsive happening, it is the sensor that a kind of true coulomb analyses. This kind of sensor uses successfully at: Gas of hydrogen of carbon monoxide, vulcanization, hydric, ammonia, hydrazine, wait for gas detect in, it is the mainstream sensor that at present poisonous and harmful gas detects. (3) , sensor of thick poor batteries gas, the gas that has electrochemistry active is in the two side of electrochemistry batteries, the meeting is initiative form strong poor electromotive force, the chroma of the size of electromotive force and gas is concerned, the successful example of this kind of sensor is a car with sensor of electrolyte of aerobic sensor, solid carbon dioxide. (4) , sensor of limiting current gas, the limiting current in one kind measures sensor of aerobic pH indicator to use report to convert a pool and carry stream child the principle preparation oxygen related chroma (gas) chroma sensor, the oxygen that is used at the car detects, detect with chroma of the oxygen in molten steel. At present the main supplier of this kind of sensor spreads all over a whole world, basically be in Germany, Japan, United States, add supplier of a few Europe newly recently: England, Switzerland. China starts in this domain early, but industrialization course result not beautiful. 5, the gas with infrared gas major sensor is in in infra-red area has a feature to absorb a peak, detect the absorption that the feature draws peak position circumstance, with respect to the chroma that can decide some gas. Past of this kind of sensor is large analytic instrument, but some closer year, as the development of the sensor industry that is a foundation with MEMS technology, the bulk of this kind of sensor already by 10 litres, 45 kilograms gigantic without bully, reduce 2 milliliter (big toe size) the left and right sides. Use need not the infra-red detector of modulation illuminant makes an instrument complete without mechanical movement component, complete implementation maintenance-free is changed. Infrared gas sensor differentiates effectively aeriform sort, accurate determine aeriform chroma. This kind of sensor uses successfully at: Of carbon dioxide, firedamp detect. At present this is planted " sensor " the supplier is in Europe! China is in this one domain is at present " half " blank! 6, magnetic oxygen sensor the core that this is magnetic oxygen analyzer, but also had come true at present " sensor is changed " process. It is the principle preparation that the oxygen in using air can be attracted by strong magnetic field. This kind of sensor can use at oxygen only detect, alternative wonderful. Only azotic oxide can produce little effect in atmosphere environment, but because these disturb aeriform content often very few, so, of technology of magnetism oxygen analysis it is exclusive almost optionally! Product of old brand industry, whole world each district has manufacturer. (of course what I say is the aerobic analyzer that serves as appearance, it can be regarded inside certain limits sensor. And this kind of product that produces with dinkum sensor form, it is the closest thing. ) 　 of 　 　 　 7, other in recent years, as the ceaseless emerge in large numbers of new technology, sensor technology also is in gas to producing corresponding revolution ceaselessly. The sort of aeriform sensor also is in as add Xin Ding. But, whether should be some sensor listed in aeriform sensor under one's name quite open to question, for instance: PID detector, although also be,be used at gas detect, although bulk is same cabinet, but, because cannot realize maintenance-free to change truly, accordingly, this kind equips, no matter bulk has many small, should list in " testing instrument " under one's name. Additional, the optical sensor development that is a foundation with optical fiber is swift and violent, although still do not have pair of electron sensor to form absolutely " minatory " , but its peculiar dominant position, shine brilliantly one day probably. Finally, be engaged in the businessman that aeriform sensor sells, for oneself business purpose, exaggerate sometimes the ability of some kind of specific sensor, the classification of promiscuous sensor, these go against an user to use aeriform sensor correctly, be in especially forum of a few sensor. Every have beg buy information, bring about instantly a large number of: "My sensor can satisfy your need! " volatile reply. Actually, the production of the application of sensor and sensor is same, also be a knowledge! CNC Milling