As the ceaseless development of market economy and science and technology, the development that builds a domain also change quickly, people is higher and higher to the requirement of life quality, the building decorates illuminative level also subsequently heighten, so indoor air pollutes a phenomenon to accompany sb is followed and also be born.

 

Origin of indoor and main contaminant

 

The origin of indoor air contaminant basically has 5 sides:

 

1, pollution of the air outdoor, the NOx in the dust in atmosphere, car and industrial waste gas, CO, SO2 and but inspiratory grain content.

 

2, the building decorates material and indoor facilities, relevant contaminant if apperception of phenolic aldehyde colophony, Niao aldehyde colophony adds up to the formaldehyde in content, a variety of bacteria that add wet agent to bring, fungus and spore, the; poison such as a variety of volatile organic matter in adhesive is qualitative, expiratory in contain 16 kinds of volatile toxic material.

 

 

3, does radioactivity pollute: ? Blow the radionuclide such as radon of? of Piao of  of Hui imperial order falling into oblivion, thorium, radium. The radon that foundations ground itself permeates reachs his child body and the radioactivity material in all sorts of housing materials. Among them, the building of the natural stone material such as the building materials marble that C ray comes from a building, granite or waste residue of mix into industry decorates brick of material, pottery and porcelain to wait. Radon reachs his child body originates building materials is like granite, brick the gas, water of arenaceous, cement, gesso and pollution of source sufferring radon.

 

4, does biology pollute: ? Bank of ⒎ of  bang  whoop  identifies mould of spic of shape of bacterium of Fu? aspergillus, grape to wait for fungus, bacteria, pollen, bug mite. Below natural condition, majority of contagion of human respiratory tract is the pathogenic bacteria that transmits infection indoors. The virus that causes respiratory tract infection only has 200 to plant, the happening of these infection the majority travels through air indoors.

 

Technology of indoor contaminant prevention and cure

 

Measure to indoor empty temperament as people value the progress with the technology, measure of indoor pollution prevention and cure with each passing day grow in quantity. Basically adsorption is purified, technology of anion of oxidation of ultraviolet disinfection, chemical disinfection, smooth catalysis, air, biology is purified, the plant is purified etc. The glazed catalysis oxidation with rapidder in last few years development and the technology of its and union of other technology photograph.

 

Smooth catalysis oxidizes

 

Principle of technology of smooth catalysis combustion is to use titanium dioxide (TiO2) undertakes smooth catalysis, use those who include solar energy inside directly the ultraviolet light of all sorts of origin, right below normal temperature all sorts of organic undertake decomposing with inorganic contaminant or oxidize, its are decomposed become H2O and CO2, achieve purify airy purpose [4] . Classics report, below the ultraviolet light of wavelengh 254 Nm, make carrier with fiber of activated carbon of smooth activator TiO2, undertake to formaldehyde adsorption and smooth catalysis oxidize, the formaldehyde of 96% by purify [5] . Advantage of smooth catalysis oxidation is specific power consumption low, operation is simple, polluting; defect without 2 is to use sun’s rays efficiency rate of low, response is slow. Document points out, will smooth catalysis oxidizes and what the synergism between different technique will raise harmful gas can be pass when other technology is compound take off except the effect.

 

 

1, of smooth catalysis oxidation and catalytic combustion technology compound

 

Undertake platinize to TiO2, 333K is in temperature or taller when, the oxidation that volatile organic matter is like the VOCS with the not tall active such as toluene, ethylene changes the effect to rise. Below the joint action of hot catalysis and smooth catalysis, can realize all oxidation of all pair of VOCS.

 

2, of smooth catalysis oxidation and adsorptive technology compound

 

Get on harmful gas adsorption in activator through sorbent, undertake in its surface catalysis reacts again, can make harmful gas arrives in shorter time inner diffusion activator surface, make exterior gas chroma increases, accelerate response rate, aggrandizement take off except the effect. The activated carbon that accumulates with comparing the face high is sorbent, laden on HZSM-5 element sieve TiO2 makes activator, below ultraviolet light illuminate, formaldehyde chroma is inside 10min by 1. 0mg/m3 falls for 0. Do not detect almost after 1mg/m3; 90min formaldehyde.

 

3, of smooth catalysis oxidation and plasma technology compound

 

The active particle such as the O-(that this technology uses a large number of high-energy electron bombard to arise or O2-) and OH- , make organic matter element is decomposed for CO2 and H2O, the radiate as ultraviolet light still can have the effect of antiseptic disinfection. Undertake dividing an experiment to 3 chloric ethylene through using plasma and smooth catalysis, when discovery uses both alone, rate of degradation of 3 chloric ethylene is respectively 32. 0% with 141% , and mix plasma when smooth catalysis is compound, its degradation rate achieves 75.4%[8] . This shows, there is apparent synergism between plasma and smooth catalysis, the response that can heighten activator significantly is active.

 

Ozone purifies a technology

 

Because ozone is slight ion to integrate system, combine condition pole to be not stabilized, can slow below normal temperature decompose oxygen, odd oxygen depart comes out, after ozone participates in material to decompose reductive into oxygen. To formaldehyde, carbon monoxide decompose mechanism to be as follows:

 

Formaldehyde: 3HCHO+2O3y3H2O+3CO2, carbon monoxide: CO+O3yCO2+ O2 considers to make clear, low density ozone (0. 050~0. 075mg/m3) can purify pollution of indoor air formaldehyde, purifying rate is 42% .

 

Defect is ozone it is one kind is had excitant the harmful gas with strong oxidisability, can pollute indoor air.

 

Air anion technology

 

Air anion technology on one hand can as adsorptive as the appearance of little grain substance in indoor air, become electrified big ion to sedimentation, make sex of report of bacterial protein surface layer polar on the other hand produce reverse, make bacterial death, very beneficial to the health of human body. Does the emissive technology of air anion basically have: ? Generator of anion of air of series of?HE of rice huller of Chinese catalpa of flute of J of  of ⑸ of Zhuo of group of head of  of ⑸ of  of ⑺ of Yun of entangled Wei Nuo makes radon child body chroma is reduced apparently 50% the left and right sides. The advantage is lead plane petty gain, noise is little, defect of bulk small; is particle was not collected or filter the effect is poor, generation ozone, cause pollution 2 times.

 

 

Biology purifies a technology

 

Content of air pollution of biology law processing is a burgeoning technology, advocate if the poriferous filling surface in filter is enclothed,have biomembrane, the microbial posture contact inside contaminant and film produces biochemistry to react, make its complete degradation is CO2 and H2O. [11] biology purifies a technology basic method has biology to filter law, biology catharsis law, biology absorbs a law to wait. Pass the filter tower of biology soil prime when NO, the result imports chroma to be 211mg/m3 when NO, when retention period is 2min, NO purify rate is 60% the left and right sides [12] . Qiang peace studied biology drop colander purifies toluene waste gas, does the result make clear: ? Brag Chinese arrogate to oneself gnaws makeup reef ∈ kills ∮ ?80g/ms, retention period 15. Below the condition of 73s, apparent is enraged fast when 230m/h, can carry the purifying rate of 90% above.

 

VOC reachs his to endanger

 

VOC, namely volatile organic matter (Volatile Organic Compounds) . American environment arrange (EPA) is to the definition of VOC: Besides carbide of carbon monoxide, carbon dioxide, carbonic acid, metal, carbonate and carbonic acid ammonium, any compound of actinic reaction containing carbon in sharing air. 100 divisions are opposite Baidu the description of VOC is: In the air of formal consist in that “ can evaporate below normal temperature, the its noxiousness, excitant, sex that cause cancer and special odour sex, can affect the skin and mucous membrane, to human body generation acute damages …… is a kind of important air contaminant. ”

 

 

Certain consistency is reached in bedroom air when VOC, people can begin to feel a painful, disgusting, limb is lack of power if; continues to linger for long, meeting harm liver, kidney, cerebra and neurological, cause possibly even convulsive, insensible, bring about memory to drop, bring serious consequence. VOC harm is so serious, can is it from why and come? The expert points out, the building materials such as wall, ceiling, ground, and the main source that the adornment material such as emulsioni paint, wall paper, heat insulating materials, adhesive is VOC. Is need special is those who point out: ? Target Jie raiseds paths between fields OC of Mo of cape of grand of graceful couch of Mei of J A Chinese-style unlined garment, basically come from the VOC at raw material, include formaldehyde, ammonia, glycol to wait, the VOC content that controls raw material so is crucial!

 

VOC of tall pH indicator is showing the intimacy that affects resident in indoor air. CO2 is dull, but VOC odour is very heavy, and major VOC makes a person unpleasant. Additional, the influence of the VOC in air is to let a person feel uncomfortable not just. Bureau of American country environmental protection (EPA) website listed short-term affect with long-term health, point out these VOC in affecting likelihood and indoor air are concerned. These influences that EPA points out include: Eye, nose and throat have exciting feeling; to have a headache, lose coordinate and disgusting; damages liver, kidney, and a few organic matter can bring about; of central nervous system some are suspected even or foregone meeting brings about animal cancer; human cancer.

 

Empty temperament measures sensor of detected puissant weapon ——

 

Detect the technology is people understanding and a kind of when transform the world necessary main technique step. And sensor is scientific test and industrial production the to information natural resources development in the activity is gotten, transmit as main as a kind of processing tool.

 

Aeriform sensor is a kind of sort that can feel some kind of gas in the environment and pH indicator device or parts of an apparatus, and can so that measure gas to undertake monitoring at treating, its pertinent information changeover is telegraphic date, analysis and call the police. Accompanying what people asks to ambient air quality to rise, the demand of detector of admirable to function sensor of portable online gas and demand are higher and higher also, a perfect aeriform sensor should have the following characteristics:

 

(1) is alternative good, to be being measured gas has apparent response in the environment that can coexist in a variety of gas diagnostic;

 

(2) sensitivity is tall, have detect widely limits and low check go out be restricted;

 

(3) signal is answered and restore rate fast, and reversibility good;

 

(4) fights the interference such as electromagnetism capability is strong, reappearance and stability are good, have be saved longerly and service life;

 

(5) structure is simple, cheap of low cost price, use and maintain convenient;

 

(6) is small-sized and portable, intelligence is changed and muti_function change, facilitate online spot is analysed.

 

Sensor of common VOC gas basically divides according to its job principle it is 3 kinds big: Electrochemistry gas sensor (wait like resistor, electric current, impedance, potential) , optical kind of sensor (include spectrum to absorb model, fluorescent law, visible law) and quality gas sensor (for example quartz crystal small balance and sensor of gas of exterior sound wave) etc. According to gas quick material can be divided for material of semiconductor metal oxide, organic polymer material, inorganic – organic composite material. In recent years, the development trend of aeriform sensor is miniature is changed, intelligence is changed and muti_function change.

 

The working principle of VOC gas sensor

 

 

VOC component itself can detect a variety of VOC, offer the opposite output that correspondence changes at VOC chroma. Should deploy board when carrying processor, this sensor still can calculate the equivalent relative value of a variety of VOC. Because the output of these component is opposite, because this does not need calibration.

 

Additional, still have sensor of gas of a kind of absolutely output: Ideal is for the application that they close to safe remote also is necessary choice, in these application, certain gas chroma is met high too opposite life is healthy perhaps constitute direct menace. Component of this kind of absolutely output normally: Opposite costlier; can detect only; of a kind of gas needs fixed calibration to output data well and truly in order to offer.

 

These elements in application are monitored in IAQ apparent undesirable. VOC sensor is important to this kind but finite and absolutely the complement that measures a source: This kind of sensor can detect a variety of VOC, because this can be used at detecting by one plant or the indoor air that a variety of VOC compound cause tastes simple change —— and this meeting affects the person inside the building.

 

Monitor in IAQ in, for example Ams CCS811(2.7mm X 4mm X 1.1mm, LGA is enclosed) or the integrated sensor that IAQ-CORE(receives crural layout to be 15mm X 18mm modular group) wait for broadband chart sensor, be not some kind of special gas that passes application in the light of safe remote to report its are absolutely Ppm value, a variety of VOC pH indicator in providing an environment however are worth relative to change.

 

In the IAQ application that monitor, VOC sensor can be used together with sensor of absolutely output CO2, offer for CO2 chroma at any time what cut truly is fiducial. VOC sensor fills strong the measurement of absolutely CO2, collect the other data of concerned VOC incident, these data are not certain with habitant (it is the main reason with CO2 elevatory chroma normally) direct and relevant.

 

 

A few kinds of empty temperament measure detected main sensor

 

Metallic oxide semiconductor type sensor

 

Type sensor uses metallic oxide semiconductor to be measured aeriform sorption, change the electrical conductivity of semiconductor, through the comparison that electric current changes, arouse call the police circuit. The environment suffers when be being measured as a result of semiconductor type sensor the impact is bigger, output line form is not stable. Metallic oxide semiconductor type sensor, because its response is very sensitive, the field that reason uses extensively at present is the small leakage phenomenon that measures gas.

 

Change combustion type sensor

 

Principle of sensor of catalytic combustion type is current use the most extensively detect one of principles that can burn gas, have output line form good, index is reliable, low-cost, wait for a characteristic without the alternate interference that can burn gas with other blame. Sensor of catalytic combustion type uses Huisi to understand bridge principle, in inductive resistor and environment can light aeriform happening not to have blaze burning, it is temperature makes the block value of inductive resistor produces change, break bridge balance, the made voltaic signal that outputs stability, the enlarge of circuit of repass later period, stability and processing indicate reliable numerical value finally.

 

Calm potential electroanalysises type sensor

 

Calm potential electroanalysises type sensor is to measure poison at present kind a kind of technology that the spot uses the most extensively, respect abroad technology is here banner, because this kind of sensor counts an import mostly. Does calm potential electroanalysis the structural: of type gas sensor? Ao of show off post ancients name for a water catltrop now shoot a glance at is foolish be able to bear or endure dark blue enters dimple? farring away to install the job electrode, right electrode and ginseng compare electrode, electrolyte is full of between electrode, by poriferous of make it of 4 fluorine ethylene diaphragmatic, enclose in coping. The join of preamplifier and sensor electrode, in the potential with brought to bear on definite between electrode, make sensor is in working status. Gas and the working electrode inside electrolyte produces oxidation or reductive reaction, returning to electrode happening former or oxidation reaction, the balance potential of electrode produces change, metabolic value and aeriform chroma become direct ratio.

 

Buddhist nun of Jia cut down sensor of cell type oxygen

 

Buddhist nun of Jia cut down the structural: of sensor of cell type oxygen? Call on ancients name for a water catltrop first another name for Guangdong Province of  of abdomen of  of v/LIT all over the ground instep of discharge of dam of widow of unreal of terpene Jian bursa of?0-30μm of ⒑ of personal Mei copy get together 4 fluorine ethylene breathes freely film, in its container inside tightens adhesion precious metal (platinic, gold, silver) shade electrode, the sky beyond part of another inside in container or container forms positive pole (change the trend with plasma of lead, cadmium big metallic) . Change potassium with oxyhydrogen. Oxygen produces oxidation in shade positive pole when passing electrolyte reductive reaction, make zincous metal ionization, release an electron, of voltaic size and oxygen more or less to become direct ratio, because zincous metal has in whole reaction,use up, so sensor needs to change regularly. Domestic technology is at present mature with each passing day already, completely OK and homebred change this kind of sensor.

 

Infra-red type sensor

 

Infra-red type sensor uses all sorts of elements to be opposite the absorption of a certain specific wavelengh principle, it is good to have the noxiousness in fighting, reaction delicacy, to most hydrocarbon respond. But the structure is complex, cost is high.

 

Sensor of gas of PID smooth ionization

 

PID by ultraviolet the body such as lighting source and ionic room is formed, have in ionic room negative electrode, form electric field, wait for measure gas to be in ultraviolet below the illuminate of the lamp, ionization, generate anion, electric current is formed between electrode, output signal via enlarge. PID has sensitivity tall, without toxic problem, the advantage such as on the safe side.