Summary of the invention
In consideration of it, the present invention provides scatter-type smoke detector assay device and the demarcation side that need not standard smog sample
Method.
It is an object of the invention to be realized by such technical scheme, smoke detection based on laser defusing measure principle
Device assay device, including calibrating instrument and marking apparatus, described calibrating instrument includes that calibrating instrument processes circuit, is provided with the first transparent window
20 and second transparent window 21 measurement chamber 14 and the first photoelectric sensor 13, described marking apparatus includes the second photoelectric sensor
17 and trigger 18;Measuring beam 23 is incident by the first transparent window, by the second transparent window outgoing after tested smog;Described
The light intensity of the scattered beam that the first photoelectric sensor 13 is formed through the scattering of tested smog for detection;Described second photoelectric sensor
The light intensity of 17 transmitted light beams formed through tested smog for detection;Described trigger synchronize trigger the first photoelectric sensor and
Second photoelectric sensor.
Preferably, described first transparent window 20 and the second transparent window 21 are axially respectively arranged at survey along measure chamber 14
The both sides in amount chamber;Described scattered beam is from the first transparent window outgoing, and described transmitted light beam is from the second transparent window outgoing;
Or the ring light electric transducer that described first photoelectric sensor and the second photoelectric sensor are integrated, described
Ring light electric transducer has internal ring detection region and outer shroud detection region, and the light intensity of scattered beam is by outer shroud detection region inspection
Surveying, the light intensity of transmission light is detected region detection by internal ring.
The two of the purpose of the present invention are to provide and use said apparatus to carry out the method demarcated, and comprise the following steps:
1) aerosol generator produces smog, is passed through measurement chamber after smog is relatively stable;Trigger output pulse, triggers the
One photoelectric sensor and the second photoelectric sensor gather data and store;
2) regulation aerosol generator, changes the concentration of smog, the output pulse of trigger randomness in the process, triggers
First photoelectric sensor and the second photoelectric sensor gather data and store;
3) step 2 is repeated) repeatedly;
4) removing significant singular value in test data, paired data fits to curvilinear equation, abscissa is scattered light
Power, vertical coordinate is transmitted optical power, determines the maximum deviation value of test data and matched curve;
5) curve coefficients is write in the program storage of smoke detector.
Preferably, in step 1) front step A that also includes: described step A, particularly as follows: keep the clean state measuring chamber, rises
Flip-flop output pulse signal, triggers the first photoelectric sensor and the second photoelectric sensor gathers data and stores.
Owing to have employed technique scheme, present invention have the advantage that:
The present invention utilizes electronic synchronizer device high-speed synchronous to trigger first photodetector and the second of marking apparatus of calibrating instrument
Photodetector, it is achieved to smog scattered light power and the synchronous acquisition of transmitted optical power, sets up scattered light and changes with transmission light
Accurate functional relationship, overcoming in reality cannot the difficult problem of manufacturer's standard smog sample.During application smoke detector, according in advance
The function established, is gone out the transmitted optical power of smog, thus obtains the shading rate of tested smog by the scattered light power counter-calculation surveyed
Or concentration.The method has without standard smog sample, the timing signal smokescope advantage such as arbitrarily, it is adaptable to scatter-type smog passes
The calibrating of sensor or staking-out work of dispatching from the factory.
Detailed description of the invention
Below with reference to accompanying drawing, the preferred embodiments of the present invention are described in detail;Should be appreciated that preferred embodiment
Only for the explanation present invention rather than in order to limit the scope of the invention.
The suspension particulate that fire produces forms smog, and particle content is the highest, then smokescope is the highest, the screening to light
Block effect the best, otherwise also set up.Therefore, use shading rate to weigh the height of smokescope, it is determined that the developmental stage of fire or
The order of severity.Mine smoke sensor accurately estimates smokescope with the shading rate of 1m thickness smog, and its mathematical definition is:
Wherein, S is shading rate, IiFor input light intensity, IoFor the transmitted light intensity through 1m thickness smog, T=I0/IiFor thoroughly
Light rate.
The mensuration of assay device shading rate obeys formula (1).By volumetric constraint, the smog that assay device measuring beam passes is thick
Degree is not up to 1m, and the shading rate of actual measurement need to calculate the shading rate of 1m thickness smog equivalence.Assume tested smokescope relatively
Low and uniform, ignore the interaction between smoke particle, and use collimated monochromatic ligth vertical irradiation.According to langbobier law,
The smog light transmittance T of measuring beammIt is respectively as follows: through the light transmittance T of the identical tested smog of 1m thickness with it
Wherein, IilLight intensity, I is inputted for measuring beamolFor measuring beam transmitted light intensity, K is fume absorbent coefficient, and C is cigarette
Fog particles concentration, l is the thickness (unit: m) that measuring beam passes tested smog.Bring formula (2) into formula (3).Obtain:
Formula (4) is substituted into formula (1), then the shading rate of 1m thickness smog is:
At fire commitment, smokescope is relatively low, and smoke particle particle diameter is concentrated mainly on few tens of nanometers scope[5],
If I directly measured by assay deviceolAnd Iil, and calculating smokescope by formula (5), it is measured, and sensitivity is poor, error is bigger.Thing
In reality, when a branch of collimated monochromatic ligth irradiates smoke particle, scattering phenomenon also will occur.Cigarette is reflected by the change of scattered light intensity
The change of fog particles concentration, i.e. utilizes the scattered light intensity I of measuring beamslIndicator transmitted light intensity Iol, it is thus achieved that high sensitivity, high-precision
The measurement result of degree.Set up functional relationship accordingly:
Iol=f-1(Isl) (6)
In like manner, formula (6) being substituted into formula (5), the formula (1) of unmodified is transformed into:
Because of smoke particle particle diameter and the spatial distribution of density and the randomness of time, reality is difficult to manufacturer's standard concentration
Smoke particle sample, uses conventional scaling method to be accurately determined IslAnd IolFunctional relationship, exist great technology be stranded
Difficult.In the present invention, use high speed flip flop to synchronize to trigger scattered light and the photoelectric sensor of transmission light measurements, compare smog grain
Sub-density and the change of flow velocity, if the response time of photoelectric sensor and difference thereof are the shortest, then it is believed that the two measure be
Same smog object.Thus, in the calibration process of device, the photoelectric sensor that device carries is in off-axis orientation measurement Isl, profit
With the high precision photoelectric sensor demarcated outside device at axially measured Iol, obtain the I that a certain concentration smog is correspondingslAnd Iol。
Repeat the above steps, it is thus achieved that the I that variable concentrations smog is correspondingslAnd Iol.On this basis, removing significant singular value, segmentation is intended
Close IslWith IolFunction curve, so that it is determined that go out f-1。
Based on above-mentioned thought, the present invention provides a kind of smoke detector assay device based on laser defusing measure principle,
Including calibrating instrument and marking apparatus, described calibrating instrument includes that calibrating instrument processes circuit, to be provided with the first transparent window 20 and second saturating
The measurement chamber 14 of bright window 21 and the first photoelectric sensor 13, described marking apparatus includes the second photoelectric sensor 17 and trigger
18;Measuring beam 23 is incident by the first transparent window, by the second transparent window outgoing after tested smog;Described first photoelectric transfer
The light intensity of the scattered beam that sensor 13 is formed through the scattering of tested smog for detection;Described second photoelectric sensor 17 is used for detecting
Light intensity through the transmitted light beam that tested smog is formed;Described trigger synchronizes to trigger the first photoelectric sensor and the second photoelectric transfer
Sensor.
Fig. 4 is backward type scatterometry and demarcates light path schematic diagram, and wherein calibrating instrument uses split type setting with marking apparatus
Put.
Described first transparent window 20 and the second transparent window 21 measure chamber along measuring axially being respectively arranged at of chamber 14
Both sides;Described scattered beam is from the first transparent window outgoing, and described transmitted light beam is from the second transparent window outgoing.
Described calibrating instrument also includes extender lens 9, spatial filter 10 and the collimating lens 11 set gradually;Described demarcation
Instrument also includes that collecting lens 16, described collimating lens and collecting lens are arranged on the both sides measuring chamber, the emergent light of collimating lens
Entering in measurement chamber, the scattered beam formed through smog 19 scattering enters in the first photoelectric sensor 13, through smog transmission
The transmission light formed enters in collecting lens, and the emergent light of collecting lens enters in the second photoelectric sensor 17.
Fig. 5 is forward-type scatterometry and demarcates light path schematic diagram, and wherein calibrating instrument and marking apparatus use integral type to set
Put.
The ring light electric transducer that described first photoelectric sensor and the second photoelectric sensor are integrated, described ring
Shape photoelectric sensor has internal ring detection region 171 and outer shroud detection region 172, and the light intensity of scattered beam is detected region by outer shroud
Detection, the light intensity of transmission light is detected region detection by internal ring.
Described calibrating instrument also includes extender lens 9, spatial filter 10 and the collimating lens 11 set gradually;Described demarcation
Instrument also includes that collecting lens 16, described collimating lens and collecting lens are arranged on the both sides measuring chamber, the emergent light of collimating lens
Entering in measurement chamber, the transmission light formed through smog transmission enters in collecting lens, the converging light of the formation of collecting lens
Bundle enters into the endocyclic area of ring light electric transducer, and the scattered beam that collecting lens edge is formed enters into annular photoelectric sensing
The outer region of device.
Described caliberating device also includes aerosol generator, and described aerosol generator is connected by gas circuit with measuring chamber.
As it is shown on figure 3, described aerosol generator includes that flue 7, described flue are provided with smoke inlet 4 and aerosol outlet port 1,
Being provided with air pump 5 in described flue, smog, under the driving of air pump, enters flue through smoke inlet and circulates.
In the present embodiment, aerosol generator uses ring-shaped flue, and its inner wall smooth, inner and outer diameter is respectively 300mm and 420mm.Cigarette
Electric filament disc 3 is set outside road, is used for heating defat cotton sliver to produce smog.Under the driving of air pump 5, smog is through air inlet pipe
Road enters ring-shaped flue and circulates, and improves uniformity and the stability of smoke particle density spatial distribution.Flue is arranged
Having twice drainage screen, i.e. air inlet screen 6 and exhaust screen 2, smoke particle particle diameter is limited in 8um and following by air inlet screen,
The effect of exhaust screen is that the adverse current preventing smog is polluted.Described smoke inlet is arranged on air inlet screen rear end.
Described calibrating instrument includes measurement light source 8, extender lens 9, spatial filter 10 and the collimating lens 11 set gradually,
Described marking apparatus also includes that collecting lens 16, described collimating lens and collecting lens are arranged on the both sides measuring chamber, collimating lens
Emergent light enter into measurement chamber in.
In the present embodiment, measuring light source 8 and use solid state laser, its emergent light is after extender lens expands, by space
Filtering intercepts the more uniform beam center portion of light distribution, then becomes measuring beam after being collimated by collimating lens.Measure light
Bundle passes perpendicularly through and irradiates and flows through the tested smoke particle group measuring chamber.
As to further improvement of this embodiment, described calibrating instrument also includes being arranged on collimating lens and measuring between chamber
The first diaphragm 12 and be arranged on the second diaphragm 15 measured between chamber 14 and collecting lens.Diaphragm is used for preventing paraxial veiling glare
To the interference measured.
Fig. 3 show the process circuit theory diagrams of calibrating instrument.Described calibrating instrument processes circuit and includes amplifier, A/D mould
Block, DSP, pump control module, temperature control modules, memorizer, touch screen, communication interface and audible-visual annunciator
The output of scattered light electric explorer, after precision amplifier and 16 A/D conversions, inputs dsp processor.Its
In, power reference provides reference power supply for A/D converter, and its temperature drift built-in reference power supply of coefficient ratio transducer is much smaller.At DSP
Reason device is the core processing circuit, and undertaking of task is the air pump within control aerosol generator and calibrating instrument, regulation laser
Device operating temperature, sound and light alarm signal export, and communication and data calculating etc..By built-in calibrating procedure, dsp processor
Output pulse signal, the synchronizer trigger outside linkage, by the original data storage of demarcation to data storage and upload in good time.
Realize man-machine interaction by LCD touch screen, show the various data such as verification result, state.If desired can by communication interface with
Data are uploaded by RS485 or ICP/IP protocol, or receive host computer instruction and data.
When applying assay device, the luminous power measuring light source uses laser instrument output nominal value, need to take temperature control
Measure ensures the stability of measuring beam luminous power, reduces temperature drift.Therefore, assay device includes semiconductor cooler and adds
The thermostat that heated filament is constituted, is controlled by temperature control algorithm by the DSP of calibrating instrument, make the operating temperature of laser instrument be maintained at 25 ±
In the range of 2 DEG C.Theoretical by Mie, the particle of same particle diameter is the most notable to the scattering of short wavelength, and the wavelength of measuring beam should appropriateness
Shorten.In this example, centre wavelength 405nm of the ripple that laser instrument sends, live width 30nm, emergent power 2mW.
In this example, scattered light power measured by the first photoelectric sensor, and sensitivity is higher, dark current is less, and peak value rings
Answering wavelength is 30 ° near measuring beam wavelength, central axis with the setting angle of optical axis.For ensureing to be sampled as same smoke particle
The scattered light of group, relative to mist flow rate and measuring beam diameter, the output response time of the first photoelectric sensor device should be tried one's best
Little, the photoelectric sensor response time of calibrating instrument type selecting is 15us.
For reducing the impact on measuring of smoke particle Spatial Density Distribution uniformity and flow velocity, measuring beam diameter and wearing
The smog thickness crossed wants appropriateness.Through overtesting, taking a diameter of 2mm of measuring beam, the smog thickness axially irradiated is 20mm.First
The synchronous error of photoelectric sensor and the second photoelectric sensor is the least, and when demarcating calibrating instrument, external electrical microsyn output is double
The time error of road pulse is less than 10ns.
According to above-mentioned assay device, the present embodiment also provides for a kind of smoke detector mark based on laser defusing measure principle
Determine method, specifically include following steps:
1) according to shown in Fig. 4, the first photoelectric sensor of alignment detector and the second photoelectric sensor on optical table;
Trigger is connected to the first photoelectric sensor and the second photoelectric sensor;Utilize and gather trachea connection aerosol generator and measurement
Chamber.
2) calibrating instrument measures chamber holding clean state, start trigger output pulse signal, triggers the first photoelectric sensor
Gather data with the second photoelectric sensor and store.
3) aerosol generator heating defat cotton sliver produces smog, is passed through detector after smog is relatively stable.Start trigger
Device output pulse, triggers the first photoelectric sensor and the second photoelectric sensor gathers data and stores.
4) regulation aerosol generator, changes smokescope, and randomness start trigger output pulse, triggers in the process
First photoelectric sensor and the second photoelectric sensor gather data and store.
In this reality cigarette example, change smokescope and refer to gradually strengthen smokescope or be gradually lowered smog low concentration or add
By force, reduce alternately.
5) repeat many times of step 4, generally 2~5 times, certainly can also test more times according to test needs.
6) removing significant singular value in test data, simulate the curve of scattering and transmitted optical power, abscissa is scattered
Penetrating luminous power, vertical coordinate is transmitted optical power.Determine the maximum deviation value of test data and matched curve.
7) curve coefficients is write the program storage of detector.
8) after having demarcated, withdraw the calibration facility of outside, seal at demarcation transmission light measurements position light absorbent,
Reduce the interference to measuring of the transmission luminous reflectance.Calibrating instrument must be demarcated before dispatching from the factory one by one, determines the demarcation that often set calibrating instrument is exclusive
Curve.
The present invention utilizes electronic synchronizer device high-speed synchronous to trigger the first photodetector and outside the second photoelectricity demarcated
Detector, it is achieved to smog scattered light power and the synchronous acquisition of transmitted optical power, sets up scattered light with the change of transmission light accurately
Functional relationship, overcoming in reality cannot the difficult problem of manufacturer's standard smog sample.During application smog calibrating instrument, according to establishing in advance
Function, the scattered light power counter-calculation surveyed go out the transmitted optical power of smog, thus obtain the shading rate of tested smog or dense
Degree.The method has without standard smog sample, the timing signal smokescope advantage such as arbitrarily, it is adaptable to scatter-type Smoke Sensor
Calibrating or staking-out work of dispatching from the factory.
The foregoing is only the preferred embodiments of the present invention, be not limited to the present invention, it is clear that those skilled in the art
Member can carry out various change and modification without departing from the spirit and scope of the present invention to the present invention.So, if the present invention
These amendments and modification belong within the scope of the claims in the present invention and equivalent technologies thereof, then the present invention is also intended to comprise these
Change and including modification.