CN86105818A - The CHARACTERISTICS IDENTIFICATION of material, material and object and the method and apparatus of check - Google Patents

Abstract

The CHARACTERISTICS IDENTIFICATION of material provided by the invention, material and object and/or the method and apparatus of check are gone up the device (2) of thermal excitation and are applicable to the detection system (3-6) of the thermal-radiating variation that Measuring Object produces at object (1) based on being used for.It comprises and is used to provide thermal excitation device (2) respectively and the device (11,12) of relative motion between detection system (3-6) and the object (1).Excitation apparatus is suitable for gas or flame, ultrasonic or electron beam, or other possible particles beams or the continuous thermal excitation of electromagnetic radiation release, and it can be by Mechanical Contact heating or cooling.

Description

The CHARACTERISTICS IDENTIFICATION of material, material and object and the method and apparatus of check

The present invention relates to be used for the CHARACTERISTICS IDENTIFICATION of factor of material and material and relevant therewith physics and chemical property and the method and apparatus of check.By in object, exciting instantaneous heat wave and measuring the thermal-radiating variation of object that causes thus, the present invention just may do discontiguous fully, aforesaid CHARACTERISTICS IDENTIFICATION and check the most all sidedly, for the prior art that can make comparisons, it has great improvement.

All entities or all electromagnetic radiation of the heat of emission of article with uniform temperature.For ideal black-body, go at wavelength, in wavelength interval d went into, the per unit area emitted power was provided by Planck's law of radiation:

$\mathrm{W(\lambda )d\lambda =}\frac{\mathrm{2\pi hc}}{{\lambda }^5}{\mathrm{(e}}^{\frac{\mathrm{h\; c}}{\mathrm{k\; T\; \lambda }}}\mathrm{-1)}{}^{\mathrm{-1}}\mathrm{d\lambda ,\; (1)}$

Wherein T is the temperature of object, and h is a Planck's constant, and k is the Bu Erziman constant, and c is the light velocity; W(goes into) be called the spectral radiance outgoing energy of object, for the object at room temperature (T=300k), formula (1) is given in the emission spectrum that has a maximum value near 10 mum wavelength places in the mid-infrared light spectral limit.If temperature rises, the distribution of spectrum will change according to formula (1), and the maximum position of spectrum is gone into _GreatlyWill be towards the displacement of shortwave direction; For T＞4000k, go into _Greatly

Near or be in visible-range.This displacement is described by Wei grace displacement law, can obtain a gratifying approximate value:

T·λ _max＝2897，9 K μm，（2）

It can derive from formula (1).

Be not that the object of ideal black-body can multiply by the W(that is provided by formula (1) with an effective emissivity ε (T goes into)≤1 and goes into) describe, thus obtain a good approximate value.Go in the wavelength interval ₁≤ go into≤go into ₂In, be not black matrix object per unit area emissive power by

$W({\mathrm{\λ}}_1;{\mathrm{\λ}}_2)={\∫}_{{\mathrm{\λ}}_1}^{{\mathrm{\λ}}_1}\mathrm{\ϵ}(T,{\mathrm{\λ}}^{\′})W\left({\mathrm{\λ}}^{\′}\right)d{\mathrm{\λ}}^{\′}....\left(3\right)$

Provide, for little temperature variation δ T, the variation of radiation power is in the per unit area

Because ε (T goes into) is a very complicated function that also depends on the geometric configuration of object in general, so formula (4) can not be represented with analytical form usually.

Yet W(goes into ₁; Go into ₂) and W(go into ₁; Go into ₂) both can measure by radiation detector sensitive in relevant spectral range.Although this scope is selected to such an extent that also comprise radiation maximum value wavelength and go into max usually, selecting other to detect spectral ranges may advantageous particularly and effectively.So the W(of the object that records goes into ₁; Go into ₂) possible variation will be directly relevant with the inherence variation of object temperature and/or emissivity.Now, this has been used for the standard metering technology, and commercial equipment has had way back.This method is a contactless type, thereby does not influence Measuring Object.Yet, because it is passive, thereby temperature that can only Measuring Object appearance itself and those contrasts of emissivity; Be similarly this method and may be provided with restriction there from the data that measuring object is recovered to.Sensitivity is also quite low, to can observed temperature contrast finding generally to be limited in 10 ^-1～10 ^-2In the k scope.

In recent years, developed (list of references 1) a kind of active measuring method that is called light-heat radiation survey art (PTR).By locating portion's thermal excitation, for example by irradiation, cause temperature variation in the object, and measure the variation of the thermal-radiating amplitude, phase place or the time that produce in the place of object exposure.At first, it is to be used for the direct measurement (list of references 2) that exposure part temperature rises under the influence of intense radiation, but now, the possibility of measuring technique has been expanded widely.In all known various light-heat radiation survey arts, shine pulsed always, be a continuous impulse sequence mostly.For the ease of analyzing, the intensity of hypothesis irradiation is humorous change usually, I=1/2 I _o(1+e ^{I2 π ft}) ₁, wherein f is a frequency, t is the time, I _oBe amplitude, also define usually a thermal diffusion length μ=(K/ π ρ fc)=( kπ f) ^1/2, wherein k is a thermal conductivity, and ρ is a density, and c is a specific heat, and k is the diffusivity of object materials.μ is in a recurrence interval, the distance that heat can spread in object.Also defined a light absorption length alpha (going into) ^-1, wherein, α (going into) is object materials is gone into the place at wavelength a spectral absorptance.Thus, just might calculate the temperature variation δ T(list of references 3 that in object, causes) for dissimilar objects and irradiation.As an example, consider α (going into) ^-1The situation of object thickness; Like this, object is lighttight, so, and by μ＞α (going into) ^-1And μ＜α (going into) ^-1Provide two kinds of possible situations.

For μ＜α (going into) ^-1, object is that photo-thermal is transparent, the irradiation that wavelength is gone into runs through the degree of depth of material greater than a diffusion length, finds that hull-skin temperature is

δT＝ 1/2 I _O（2πfρC） ^-1α（λ） （5）

Corresponding to the temperature fluctuation of irradiation, so just proportional with the absorption coefficient of object materials with frequency f.Under pulsed frequency f, measure heat radiation according to formula (4), make the spectral characteristic that characterizes body surface by the component that changes illumination spectra become possible (list of references 4), just produced the method for a new spectroscopy thus.

For μ＞α (going into) ^-1, object is light tight heat.So all radiation of penetrating are all absorbed by the superficial layer thinner than thermal diffusion length, the table of discovery surface temperature is

$\mathrm{\delta T=}\frac{1}{2}{I}_O\mathrm{(2\pi fk\rho C)}{}^{-\frac{1}{2}}$

So, the temperature variation that causes is just irrelevant with the absorption coefficient of object, and the measurement of the radiation outgoing energy of frequency f provides the information about parameter K, ρ, C and/or ε.This also is applicable to as K, ρ or C in object and when leaving the surface and change less than the place of a thermal diffusion length.Invisible internal structure of body will provide the amplitude of δ w and the variation of phase place on the surface.(list of references 5), in other words, this a certain degree of depth μ that just makes " seeing " to wear object becomes possibility.An interesting especially situation is to measure the variation of temperature that causes from the front irradiation of object at the back side of object.Structure in the value of K, ρ and/or the C object devious will be transmitted influential to the heat via object, and provide the amplitude of back temperature fluctuation and the variation of phase place, this just might study than thermal diffusion length thick the opaque article of manying inside (list of references 6).

The temperature fluctuation that causes can be very little, and surveyed area is 10 ^-6In the scope of K.For measurement δ w under the situation of good signal-to-noise, thereby need set up measured heat emission and the relation between the irradiation, so that those thermal oscillations with the impulsive synchronization of irradiation can be listed as by mirror.According to routine, can accomplish that by the way of using some electronic locking amplifiers that will all filter except that all signals the narrow bandwidth △ f who surrounds pulsed frequency f basically this point △ f is usually always less than 1 He Zhi.In order to obtain representational measurement, the time that is used for each measurement point must equal the inverse of bandwidth at least, so that use steady state condition.So it is slow and time-consuming measuring, and the general speed of inswept object often is lower than 1 mm/second (list of references 5,6).Though there is obstacle having obtained proof aspect the scientific analysis that is used for body surface and inner structure in this scanning technique on this methodological principle, make it not be suitable for real-time measurement.Thereby this method is not suitable for many operations, for example with various industrial products and technological process chemical substance and composition, and semiconductor element, surface coating, film shape and layer shape material, the operation that the continuous CHARACTERISTICS IDENTIFICATION of solidification process or the like is relevant with check.For also like this by rescaning the situation that forms the corresponding bidimensional of object (also may be three-dimensional) photo-thermal image soon.In all these situations, each measurement point should be accepted the measurement less than 1 millisecond.Thereby the method for static light hot radiation measurement art is slow three above orders of magnitude can not be used for above-mentioned purpose.

Produce heat transmission by diffusion, this is an irregular process, and wherein the situation of one dimension is by equation

Describe, wherein x is a coordinate, and t is the time, and T(x is at moment t, in the object temperature of an x t).For by each individual cases initial and the boundary condition decision, can find the intact of equation

Complete solution, as a kind of surface temperature T(0 of humorous change, t)=T _oE ^{I.2 π ft}Be added in length or size on the object of 0≤X≤∽ scope the time, find (list of references 7)

$T(x,t)=T_0{e}^{-\frac{x}{\mathrm{\μ}}}{e}^{i(2\mathrm{\πft}-\frac{x}{\mathrm{\μ}})}-\frac{2T_0}{{\mathrm{\π}}^{1/2}}{\∫}_0^{{\frac{x}{2\left(\mathrm{kt}\right)}}^{\frac{1}{1}}}{e}^{i-2\mathrm{\πf}(t-\frac{x^1}{4{\mathrm{k\ξ}}^1})}{e-\mathrm{\ξ}}^2\mathrm{d\ξ}.......\left(8\right)$

Last that provides by the integral representation formula be since on the object transient heat of the initial object that temperature caused distribute.When t → ∽, this instantaneous value has just disappeared, and only keeps by the time variable of first stable state that provides to separate.As mentioned above, this has described the temperature fluctuation of using in stable state light-heat radiation survey art.Separate form with decadent wave, its amplitude in equaling the whole distance of thermal diffusion length μ with factor e ^-1Reduce.Regulation constant phase item 2 π ft-x/ μ can obtain velocity of wave s=dx/dt, and it provides

$\mathrm{S=2\pi f\; \mu =2}\frac{k}{\mu }{\mathrm{=2(\pi kf\; )}}^{\frac{1}{2}}\mathrm{.\; (9)}$

See that thus heat wave is rapid diffusion, high frequency waves transmit more rapidly.Simultaneously, because the cause of factor e, high-frequency heat wave is decayed more sharp with x.According to formula (9), frequency is that the wavelength of the heat wave of f is ∧=2 π μ.

If might carry out stablizing the obtainable measurement faster of will heat wave institute, correspondingly need to use the transient silution of formula (8) than above-mentioned utilization.This requires to calculate in more detail the heat flow in the object.So consider instantaneous heating object surface to temperature T _oAn individual pulse.At degree of depth x place, object will stand to rise to maximum value and hinder instantaneous temperature drift to stationary value then.The expansion situation of this temperature wave front is by formula

$\mathrm{T(x,t)=}\frac{A}{x}\mathrm{｛1+2}\underset{1}{\overset{\infty }{\mathrm{\&Sigma;}}}{\mathrm{(-1)}}^n{e}^{{\mathrm{-\; <figure-callout\; id="2"\; label="n"\; filenames="86105818\_DRIMG4.png"\; state="\{\{state\}\}">n</figure-callout>}}^2\frac{{\mathrm{<figure-callout\; id="2"\; label="\pi "\; filenames="86105818\_DRIMG4.png"\; state="\{\{state\}\}">\pi </figure-callout>}}^2\mathrm{k\; t}}{x^2}}\mathrm{｝,\; (10)}$

Provide good being similar to, wherein, A is a constant that depends on the thermal excitation on K, C and surface.By calculating this function discover (list of references 8) x on the throne place, instantaneous

Temperature has reached half of maximum value.

As good being similar to, it is moving that this also is applied to three-dimensional heat flow.Like this, when with the point source area of heating surface of a snap, leave the shot point distance for the surface of x a bit, the transient state heat wave is in the time

Approximately reach later on half of its maximum drift value.

Thermal time constant of definable thus

τ＝ (d ²)/(π ²k) ，（12）

It is corresponding to leaving the time of being changed that any the temperature of an instantaneous shot point distance for d reaches its maximum drift at 1/3 o'clock.Thus, the available heat rate of propagation u(d that spreads is just arranged thereupon on distance d)=d/ τ is

u(d)= (π ²k)/(d) .（13）

In other words, the last available heat rate of propagation of a certain distance is inversely proportional to distance, it anticipate this point of distinguishing the flavor of diffusion time along with the distance of leaving shot point square and increase, this is that the diffusion of the stable state heat wave that provides with formula (9) is relevant.If get d=λ=2 π μ, then find, equal at wavelength frequency f a stable state heat wave wavelength apart from d on, the effective diffusion velocity of instantaneous heat wave is u(2 π μ)=π k/2 μ ≌ s, wherein s is the corresponding stable state wave propagation velocity that is provided by formula (9).

Formula (11) uses in the full sized pules method to measure the diffusivity k(list of references 9 in the solid matter): with the duration＜＜when the PULSE HEATING thickness of t is the front of 1 object according to the temperature variation measurement at the back side

, just can from

$\mathrm{K=}\frac{{\mathrm{1,37l}}^2}{{\pi }^2{\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="86105818\_DRIMG4.png"\; state="\{\{state\}\}">t</figure-callout>}}_{\frac{1}{2}}}\mathrm{.\; (14)}$

Measure k.In the period of nearest two or three, pulse method has been further development of the light-heat radiation survey art (list of references 10) of impulse type, wherein, when the front of PULSE HEATING object, the correct curve shape of the temperature variation at the record object front or the back side, can measure absorption coefficient, the thickness of thermal diffusivity and object self and the surface layer thickness that may exist.In principle, a single pulse is can measure all these parameters.In this respect, pulse method is quicker than stable state technology discussed above, this be since when frequency f and bandwidth △ f do that stable state is measured each time desired and the approximate corresponding factor of periodicity f/ △ f.Yet, characterize for example complete object with pulse method if desired, a kind of flow of raw material or the characteristic of analog, in the case, people correspondingly detail record at the temperature variation or the curve of all interested points, by each time curve independently of separate analysis, extract relevant data then.The time that this record and signal Processing spend subsequently are so long, thus impulse method is slow too for real-time measurement.This use of impulse method fails to carry out actual verification always, and reason is, the data that impulse method obtains are too many, and most of data wherein are nonsensical for the measurement of being done.This point will obtain more careful explanation when below the present invention being described.

The following fact of the present invention's foundation: as a rule, people are not interested in complete temperature curve or change procedure on each independent point of object.Thereby usually be the temperature variation observation that may occur of pointwise record body surface and differentiate that surface chemistry and the presumable difference of physical state up and down is just enough.Thereby under its most general (as what will mention in the back) situation, the utilization of the instantaneous heat wave in the lay special stress on object of the present invention writes down that the heat radiation of series of points becomes possibility on the object after making the length selected and the thermal diffusion time on the depth d postpone continuously and in real time specially in corresponding to object.In a word, the present invention guarantees to give object the motion with respect to continuous (and constant as far as possible) heat emission source, thus object and relative velocity v between thermal source to be higher than with in the object relevant apart from available heat rate of propagation u(d).Continuous Heat excite with this combination of physics motion for line just can with the sequence that on object, moves continuous separately and the thermal source of snap compare.Thermal diffusion state along the running path distance object each point bigger than d is irrelevant each other, and this is because thermal source moves sooner than thermal transient wave front: at time τ ≌ d ²/ π ²After the k from each alone the transient wave front of shot point in object, spread a distance, d, meanwhile, shot point with respect to Moving Heat Sources one distance L=v τ＞d.So in this position, object is through the visual field of bolometer detector, and is like this, the relative velocity v between detecting device visual field and object ₂Also just be higher than u(d).Like this, detecting device just detects from incoherent each independent excitation point, postponed a time τ with respect to the initial thermal excitation of this point mutually heat radiation on the object.In object, leave each independent shot point apart from the unevenness that may occur in the d,, cause that the radiant heat source of delay changes accordingly just as described above.This shows, also might utilize the transient state heat wave optionally to survey and leave each independent shot point apart from body surface physical parameter in the d.Certainly, this method also allows to write down with inspection example and is emerging in the physics of object and the structure and the figure of chemistry as selected thermal excitation by spectrum.If desired, time delay or length just can be reduced to minimum value, further propagate the caused maximum temperature drift of thermal effect that the transient state heat wave that comes out causes so that discern better from shot point.

The present invention has disclosed by the temperature that applies variation in object and has detected the thermal-radiating variation of consequent object and characterized material, the performance of material and object and/or check material, the method of material and object, it provides a relative motion between the heat exciter of object and outside, and this excitation is continuous and preferably constant in time, and it is to put on the object with the continuous form that heats or cool off of a kind of approach that relative motion was limited along object, and at object be used to measure between the visual field of detection system of the thermal-radiating variation of object that is produced a relative motion is provided, and, object to the speed of related movement of detection system visual field and external heat excitation than the available heat rate of propagation height in the object, and preferably much higher.

The present invention more carefully is described below with reference to the accompanying drawings, wherein,

Fig. 1 shows the schematic representation of apparatus that is used for by object front (top) thermal excitation.

Fig. 2 shows that front (solid line) or the back side (dotted line) by object detect thermal-radiating synoptic diagram.

Fig. 3 is the synoptic diagram that shows the example of the well-regulated and distinctive structure may be included in material and the object and figure.

Fig. 4 shows that spacing is the synoptic diagram of thermal excitation and the detection of L.

Fig. 5 is a spatial filter that interrelates with detection system.

2 pairs of speed v of thermal source in Fig. 1, have been shown with respect to thermal excitation ₁The thermal excitation of the object 1 of motion.This excites at this ideal style with point-like and explains.And in fact, it has certain extension a on direction of motion.Thermal excitation can by with an object with good thermal conductivity, may be that the sliding contact of " heat pipe " that be communicated with and heat reservoir heat or cold produces, but it can also be by hot gas or cold air under without any the situation of Mechanical Contact, electromagnetic radiation, electronics or other particle radiation or also can produce by sound wave.Gas is positioned at object surfaces with contacting to excite with initial heating or cooling, yet as mentioned above, electromagnetic radiation will extend through and generally reach α (going into) in the object ^-1Distance, this distance equals the inverse of absorption coefficient of the radiation of relevant wavelength.Therefore, go into by selection, thermal excitation can be adjusted to favourable situation to a certain extent, and particularly the detection with the material that is revealed in the surface interrelates.

Use the mutual at regular intervals part of the electromagnetic radiation of two or more different wave lengths, and each wavelength is used a detecting device separately, also might do more careful and comprehensive spectral analysis object in crosscut direction of motion.

Particle radiation depends on the elemental composition of energy and the material character and the object of particle, run through into object in the corresponding way, and this also can be used for changing exciting in the object volume.Sound wave depends on its elastic modulus E and extends through in the object and propagate in object, and this just can optionally heat the inner structure with elastic modulus E, causes sound wave to be absorbed.So just provide the arm store of a different thermal excitation mode, can select to be specially adapted to each thermal excitation of using separately of the present invention from the inside.

In order to obtain special benefit, it also is possible that the thermal excitation mode that two or more are different combines.For example, object can be along same approach or is all heated respectively or cool off along two parallel approach, for each detects independently in these.Temperature drift is reverse mutually, and it provides compensating signal in detection system.This can be used for for example emissivity being changed with hot coherent signal difference coming.

Along a neutral approach, that is to say the detection of the approach that does not have thermal excitation, give a reference signal in addition from the object that is not subjected to thermal perturbation.

Fig. 2 show when thermal excitation from one side (front) (a) and from the negative (back side) (b) detect the heat radiation of generation.As a rule, in the given measurement situation, only use a kind of in two kinds of alternative plans, but in many situations, interested is to have several detecting devices to work abreast, for example adopts the form of array.The visual field β of detection system has a speed v with respect to object 1 ₂Detection system comprises collects for one to represent with lens in figure from the thermal-radiating device 3 of object.Other are beneficial to and collect thermal-radiating device 3 can be reflector apparatus, light transmitting fiber, optical waveguide and other devices.Device 3 gathers detecting device 4 with heat radiation, and it is converted to electric signal with radiation.These detecting devices are made with semiconductor material often, and can be used in thermal-radiating different spectral range, and it depends on the temperature of object especially.But the thermal detector that has more smooth spectral characteristic in addition.These detecting devices are generally fast and sensitive not as the semiconductor detector reaction.The signal that comes self-detector is in 5 li amplifications of amplifier, and can further stand for 6 li more particularly to analyze at a unit that comprises electrical signal processing system.As described below, unit 4,5 and 6 frequency span must and speed v ₂And the size of certified structure is relevant, is met to cause formula (27).For these unit, there are not other special requirements.Can be used for realizing control and supervision effect or the like that then wherein each situation all can make it to become possibility by the present invention from information extraction in the signal processing system, this is unessential, just is not included in figure and has suffered.Front at device 3, in the position (b), also show the situation how an optical filter is settled with respect to detection system in addition, be used for further limiting spectral range and the heat radiation that is used for resisting selectively in other spectral ranges (for example from thermal excitation) and other electromagnetic radiation that heat detects.Indicated as accompanying drawing, when from the front or the back side when detecting heat radiation, most of factors are identical, and a kind of selection depends primarily on the shape of object and the situation of measuring purpose in two kinds of schemes.Two kinds of structures often provide corresponding information.When relating to thin object and material, detecting from the back side is interested and advantageous particularly.Yet this is having problem aspect other object parameters that may change and characterize the whole bulk properties of object of identifying inner structure or thickness.For structure of interest is positioned at the object at depth d place and material same situation is arranged also, this depth d makes that the resolution by the diffusion decision of front (≈ d) is low excessively.Structure of interest be revealed in the surface that type objects superficial layer research and thickness is very thick so that thermal diffusion arrives the research of inner structure that the back side will be changed the long time and cause that type objects of the corresponding reduction of resolution, on the contrary, preferably do from the front to detect to carry out.

Fig. 3 is illustrated in (3b) in the surface (3a), body or comprises the object and the examples of material of well-regulated and distinctive structure and figure in the version of the parameter (thickness as shown in FIG.) in the whole cross section that influences object.

Character and feature according to structure and figure, can select the form of suitable thermal excitation, and still detect special knack thickness and other character from the front due to object from the back side, launch by the thermal transient that time τ has postponed when detecting with respect to thermal excitation, and time τ is when adjusting to the big or small d of interested figure and structure according to formula (12), and the device 3 in Fig. 2 will provide the signal that comprises about the information of these structures and figure.

So according to existing knowledge about presumable figure and structure in the object, this just can be used to represent according to the record of these structures and figure the feature of each single body, also can be used to check the object that comprises structure thus with predetermined pattern.The structure in the object and the yardstick of figure or length d are the important parameters in this relation, and (and as the front was narrated) determined the limit of each speed of related movement of object particularly.The present invention also can be used to research and feature description on the surface with a kind of corresponding method, in vivo or pass through the object that whole transversal section has random figure or structure.This can be used for many purposes, for example identifies that in its body this is the object that the variation of parameter runs off certain limit.This also can be used to set up feedback in production run, thereby controls them, and parameters of interest is remained in the suitable extreme value.

Fig. 4 shows device and the detection system that is used for thermal excitation, its arranging situation is such, and the distance between the visual field of thermal excitation and detection system is provided by length L, if this length remains unchanged, be a steady state value, object just has same speed V=V with respect to thermal excitation and detection system so ₁=V ₂So thermal excitation and detect between fixing δ t=L/v time delay is just arranged, and provide a chance for specializing in leaving fixing structure of thermal excitation apart from the d place.And d makes formula (12) consistent with τ=δ t.So analysis that provides above and explanation just are used in many situations, also are used in the specific embodiment of the present invention.

When monitoring flow of matter or the like situation, it is very easily that a fixed device that is used for thermal excitation and detection is arranged, and on the contrary, object is moved.About the embodiment (for example in medical science) of image formation of object, more practicable is to excite and detect and cross a fixing object associated movement.

By changing V, can scan bigger or less going up apart from d=π (k δ t); This also can obtain by L can be changed, and for example makes

L＝L ₀+L ₁·F（ωt）， （15）

Wherein, L ₁＜L ₀, and F(wt) be that an amplitude equals 1, angular frequency is the periodic function of w.So the time delay between thermal excitation and detection can be at boundary δ t _Minimum=(L ₀-L ₁)/v and δ t _Greatly=(L ₀+ L ₁Change between the)/v.People can obtain the diffusion that can detect from formula (12), determine the respective range apart from d.Yet necessary condition is v always ₁And v ₂＞u(d) Here it is requires at periodic function F(wt) the angular frequency w of the lining speed WL that can make and move and interrelate ₁Satisfy.

V-WL ₁＞U（d） （16）

So this front will be applied in the whole cyclical variation of L for the condition of appearing.D changes from the object to the object in distance, or under situation about changing between the part object, when present value d the unknown, perhaps has severally when having different characteristic apart from the structure of d when object, and this embodiment is favourable.Handle based on electric signal, must obtain relevant therewith reference signal by the unit 8 of command range, so that signal processing system can be done correction for different diffusion lengths, time delay and the signal frequency that may occur.Like this, the position that changes thermal excitation corresponds to reality most, and the field positions of detection system is maintained fixed, so that the latter also fixes with respect to the speed of object, Here it is makes the frequency spectrum of explanation thermal signal more easy.

Device that causes object 1 motion is shown in Fig. 4 with roller to 11 and 12 form, and roller is to giving object with speed v by their rotation.

Another embodiment can such as comprise have follow each other corresponding to different diffusion time of τ and be positioned at a thermal excitation leaving two or more detecting devices that excite the different distance place.So this device makes the structure at certain depth place in the object for example scrutinized becomes possibility.

Fig. 5 shows the situation by spatial filter 9 shielded detectors and detection system.This makes the thermal excitation that is used for preventing object act directly on a kind of shielding mode on the detecting device often.The excitation energy of for example electromagnetic radiation mode causes scattering to proceed in the detection system, and since this radiation therefore compared with the strong several magnitude of consequent heat radiation, even actual signal can be disturbed and shelter to little scattering also.Same situation can take place such as exciting also of hot gas or cold air, this gas makes in the scope that is leaked between object and detecting device, and influence detects, irrelevant with the kind of selected thermal excitation, as a rule, excite in the scope at object, always wish shielded detector, prevent to experience instant maximum temperature drift.Usually require only detected temperatures drift after some time delays.Particularly under the very little situation of this time delay, it is main having such spatial filter.Spatial filter is made the protective cover of a complete closed unit 3 and 4 often, and an opening towards object is only arranged, and heat radiation can enter by this opening.

Be stressed that the present invention is on principle and in fact with described above stable and have any different based on light-heat radiation survey art (PTR) technology of pulse.Different with known technology, the thermal excitation of object is continuous, and in a lot of practical matter through the time stable.Yet in addition, the relative motion that importantly will indicate object has six kinds of different purposes at least.

I. at first, have v between object and thermal source ₁＞u(d) relative this motion excites a series of continuous transient heat that continuous (and may be constant) thermal excitation converts on the object, and each all has its expansion of own transient time.In other words, object of which movement makes the advantage of utilizing instantaneous heat wave and needn't become possibility by pulse excitation.

II. the second, in diffusion time τ, object guarantees that with respect to the motion of thermal source stable new instantaneous heat wave produces, and at that time, former transient wave is still in advancing.With respect to u ₁, v ₁Big more, just have more ripple (being measurement point) like this and come across during the time τ, once become possibility and each time τ is measured, because the whole time launches all to be noted down with the pulse method that a kind of maximum value mode occurs.Compare with pulse method, the remarkable advantage of the present invention on measuring ratio done more the measurement just here if desired in each time quantum, and this only passes through to improve v ₁Just can reach.

III. the 3rd, the displacement (with respect to thermal source) of the distance L in object thermal excitation district=v τ is picked out selectively to be used to note down from each independent transient temperature that is stimulated a little on the object and is launched fully with heat radiation constantly.Opposite with pulse method, in other words, the motion of object relates to, and for each independent shot point, has only noted down a point on the temperature curve.

IV. the 4th, the relative motion between object and field of detection means, come self-detector corresponding to limiting τ constantly, the temperature separately that is independent of each other is launched (because v ₂＞u(d)) thermal signal be converted into continuous time dependent electric signal, a definite shot point is one to one on the electric signal of a definite time and the object.

V. the 5th, just because of the relative motion between the visual field of object and detection system, just might regulate relative velocity v ₂Thereby the signal that makes all CONSTRUCTED SPECIFICATION to be studied provide the frequency span that usually drops on detection system changes.So just can amplify and handle these electric signal in a usual manner.

VI. the 6th, relative motion means that thermal excitation and detection are to carry out on the position that separates actually, will detect with thermal excitation with a simple method and separate, and produce thereby make to excite outside the visual field of detection system.This specially refers to, and same electromagnetic wavelength can use in thermal excitation and detect not influence (mutual interference mutually) on both.

Top description list is understood the necessary condition that the present invention can be worked, in order to simplify discussion, admitting that transient heat only excites on a very thin superficial layer of heattransfer rate much thin object apart from d produces, and the heat emission that causes also originates from corresponding thin superficial layer.This in fact also is consistent with most of interested materials and object.Therefore, the present invention has and has the method confers similar advantages now.Also can be used at least transparent and to launching the also material of partially transparent on the methodological principle as described herein for excitation portion, because the unevenness wave spectrum in object or heat both will give heat wave different starting condition, and differently influence its expansion and their radiation again.Yet this situation is more difficult to be explained, thereby as represented in (4) lining, when object materials had maximum transparency, it was favourable selecting the wave spectrum scope of an inspection side.

According to being used to implement Design of device of the present invention, also to satisfy several conditions in addition:

1, in diffusion time τ, heat wave from a shot point on the object is propagated one apart from d=τ u(d along surface (and in volume)), thereby should determine also that this method can getable vertically (that is to say, on the direction of motion of object with respect to thermal excitation) highest resolution apart from d.If as what see along the direction of relative motion, thermal excitation has a scope a＞d, and so correspondingly relative velocity v must be high to making a/v ₁＜τ, so that

v ₁＞ (a)/(d) u（d）. （17）

So the thermal excitation on each independent point on the object has a duration＜τ as the front, this means, time＜during τ, still be counted as with observed diffusion point irrelevant by this at the point of distance＞d.

If detection system can provide this resolution longitudinally, then according to common optics criterion, the yardstick of object visual field or range beta must satisfy β≤d, requirement that Here it is, the relative velocity v between the visual field of object and detection system ₂Satisfy

v ₂＞u（d） （18）

Thereby in time＜τ, the zone in one's power of the scope d on object is through the visual field.According to the present invention of top IV strip adoption, this is unquestionable; With respect to thermal diffusion process, detect and also can regard instantaneous as.

If β＞d, the range beta of visual field can provide effective longitudinal frame on the object.In order also to obtain this resolution, only require from heat wave

v ₁≥ (a)/(β) u（β）， （19）

Assumed condition is β＜a; For d＜a＜β, then only require v ₁〉=u(β), for identical vertical resolution is arranged in detection, essential satisfied simultaneously

v ₂≥u（β）， （20）

In the case, active diffusion length equals β, and effective diffusion velocity is

u(β)= (π ²k)/(β) （21）

Be τ corresponding diffusion time _β=β ²/ π ²K.

Vertically resolution just mentions this.

2, main points of the present invention are that the direction of motion at transversal object has high resolution.Suppose, in transversal direction of motion yardstick being arranged is the structure of interest of d, use resolution δ d＜＜d identify (this can for example be applied to measure object or average thickness be the variation in thickness 〉=δ d of the superficial layer of d) propagate this additional distance before the heat wave and need time δ τ, it is from derivation that formula (12) is differentiated

δτ＝2 (δd)/(u（d）) . （22）

For the structure that makes mutual spaced δ d can cause detectable variation in object is excited a little heat expansion, such requirement is just arranged; In time δ τ, object equals to offer an explanation the unit with respect to one of thermal excitation campaign apart from d() (simultaneously essential application of formula (17)).This just might detect to a certain extent in time τ and τ+thermal-radiating difference of d τ.From v ₁. δ τ 〉=d

Then have thereupon

v ₁≥ (d)/(2δd) u（d） （23）

Suppose a thermal-radiating desirable optical detection above, also promptly used β≤d.If β 〉=d then requires in time＜τ, thermal excitation is through distance beta.So, from v ₁δ τ 〉=β has to top similar thereupon

v ₁≥ (β)/(2δd) u（d）. （24）

So vertically how much resolutions are just provided by β.This also requirement simultaneously

v ₂≥ (β)/(d) u（d）. （25）

So in time＜τ, each independent point just is the visual field of β through overrange on the object, and the relatively hot diffusion process, detection still is counted as instantaneous.Even vertically the visual field of the examined system of resolution and not limited by diffusion process in other words, also still might obtain the same resolution by the heat wave decision, but relative velocity is higher at that time.

3, if the max architecture in the object of doing the characteristic discriminating and/or being verified has yardstick D, these structures must be at time D/v ₂Back warp is crossed the visual field of detection system.The inverse of this time is corresponding to a lower cutoff frequency f that must be higher than detection system _MinimumFrequency, thereby

v ₂＞Df _Minimum(26)

Just extraordinarily its detectability is remained on frequency is lower than 100 He Zhi to good bolometer detector.For D=1 centimetre and f _MinimumThe example of=100 He Zhi has v by formula (24) ₂＞100 cels are so that be that the electronic unit that the signal of 1 centimetre structure can detected system detects corresponding to size.Owing to change to 10 cels of good metal heat conductor from 10 cels of the material (plastics, paper or the like) of low thermal diffusivity in the general rate of propagation of distance on 1 centimetre, therefore, often by formula (26) decision, its value can be considerably beyond rate of propagation for the lower limit of relative velocity in object and the detection system visual field.

Suppose that vertical resolution g by diffusion restriction equals the yardstick of minimal structure in the object to be identified, so the highest frequency of signal is just by v ₂/ g provides.Thereby the essential relative velocity of selecting object and detection system visual field, to cause in scope

(V ₂)/(D) ≤f≤ (V ₂)/(g) （27）

Interior all frequencies can be positioned at the frequency span of detection system.The upper cut off frequency of bolometer detector is the order of magnitude of megahertz or higher often, and formula (27) is v ₂Selection wide restriction is provided.

Be stressed that, in principle v ₁And v ₂Be unequal, and actual conditions also it happens frequently, and useful for guaranteeing the present invention, they need be with respect to object along same approach orientation, as long as satisfy condition recited above yet.For example, v ₁And v ₂Can be along the approach orientation same with object, at that time, v for example ₂Be constant, and v ₁Change periodically up and down at a mean value.Also change periodically in thermal excitation with by the distance between the detection that diffusion time, τ provided, thereby in fact corresponding to various diffusion time of τ, the object in diffusion length d scope is realized scanning.In some occasions, perhaps still when research respectively has several structures of own characteristic length d because transversal diffusion length spectrum, make relevant apart from d for unknown or when changing, this may be favourable.

Some examples can more specifically be introduced the present invention.F is used in supposition below _MinimumThe detection system of=100 He Zhi.

A. it is interested for example studying the semiconductor inner structure on the 0.1 millimeter magnitude degree of depth.Thermal diffusivity is k=0.3 cel (for example for a germanium), from formula (13), provides the u=3 meter per second for the d=0.1 millimeter, for resolution δ d=10 ^-2Millimeter then obtains v 〉=15 meter per seconds from formula (23), and this is based on the focusing good detection system (from formula (24)) of the thermal excitation (from formula (17)) of yardstick a＜0.5 millimeter and β＜0.1 millimeter.If the out to out of record is D=1mm, then v is just arranged from formula (26) ₂＞10 cels, owing to the value that provides compared with rate of propagation u is come, this is a lower relative velocity, thereby in the case, the general requirement that can be proposed by the present invention as previously described decides v ₂, v ₂＞u(=3 meter per second).

B, lip-deep protective finish are another important applied field of the present invention.Suppose 50 microns of thick coatings, k=10 ^-2Cel (glass or analog), u=20 cel then, for the thermal excitation of yardstick a=0.5 millimeter, visual field β=0.2 centimetre and check thickness resolution require the situation of δ d=5m, provide v from formula (17) ₁＞2 meter per seconds, and provide v from formula (24) ₁＞4 meter per seconds will be so the value of back will determine v ₁For the delamination that may exist in checking on a large scale, consider D=10 centimetre possibly, and provide v from formula (26) ₂〉=10 meter per seconds, and correspondingly provide v from formula (25) ₂〉=0.8 meter per second.In the case, object determines the selection of relative motion with respect to the big young pathbreaker of the speed of detection system.

C, the measurement of thickness, for example measurement of aluminum products thickness, and find that the defective that may exist in the material is another kind of appropriate example.Thickness can be the d=5 millimeter, and thermal diffusivity is k=1 square centimeter/second, draws the u=5 cel thus.For resolution δ d=0.1 millimeter, draw v from formula (23) ₁=1.25 meter per seconds.Here, it is easy making a and β＜d.If structure to be looked into has D=1 centimetre, according to formula (26), essential v ₂〉=1 meter per second.In other words, the requirement to two relative velocities is actually equally.

D is necessary to monitor thickness in the production run of industrial products paper and synthetic material.Suppose d=0.1 millimeter and k=10 ^-3Provide the u=1 cel square centimeter/second, for the a=1 millimeter, and β=0.5, millimeter and δ d=5 micron provide v from formula (17) ₁＞20 cels, and provide v from formula (24) ₁〉=50 cels.If size goes on record for D=1 centimetre the irregular grade of defective, provide v above formula (26) resembles ₂＞1 meter per second, as a comparison, formula (25) provides v ₂〉=5 cels.

E adds the chemical substance that heat energy identification is revealed in body surface by the electromagnetic radiation that is used in the absorption line of representing substance characteristics.Suppose that absorption coefficient is α (λ)=10 ^-3/ centimetre, provide depth of penetration α (λ) ^-1=10 ^-3Centimetre.This has born the thickness of the superficial layer of the thermal excitation of having settled major part, for d=10 centimetre and k=10 ^-2Square centimeter/second, it provides u(d)=1 meter per second.If a=0.5 millimeter and β=0.2 millimeter millimeter provides vertical resolution by β=0.2.If monitor objects only requires to reach and equals absorption length α ^-1The degree of depth, then require v ₁〉=50 meter per seconds (from formula (17)) and v ₂〉=20 meter per seconds (from formula (25)).Yet in such situation, these are unnecessary high requests that relative velocity is proposed.Because requiring the horizontal resolution order of magnitude here is 10 ^-3Centimetre may not be interested, so only need limit rate of propagation u(β), it means that resolution is provided by vertical resolution β.Obtain u(β from formula (21))=5 cels.Formula (19) and (20) then provide v respectively ₁〉=12.5 cels and v ₂〉=5 cels.The max architecture of record can be a D=2mm(literal for example, line figure or analog), it provides v from formula (26) ₂＞20 cels.

According to relevant measurement situation, can be correspondingly object be calculated more accurately with respect to thermal excitation with respect to the restriction of the speed of the visual field of detection system.The basic condition precedent and the ultimate value that define this method are provided by the afore-mentioned that always must satisfy.

Top example only indicates seldom several purposes of the present invention: the check of semiconductor element and surface coating, inhomogeneity researchs such as metal material, foil material, paper are checked and approached to thickness, reading of literal, collection of illustrative plates, chromatogram or the like, the spectroscopic temperature record method that is used for the medical analysis of skin and other organs, the composition check of chemical product and analog, test and control sulfidation and other chemical processes and reaction, heating and scorching hot object or the like and fluid film.As if in all these situations, the present invention provides the new possibility of measurement, because in its most general situation, this law is complete contactless type here, and it does not influence object.This method can be implemented soon, thereby can adapt to the requirement of industrial process and manufacturing, and measurement is very sensitive, and can use ready-made technical equipment and element.

Also might utilize the present invention to discern and be present in material and interior distinctive structure and/or the figure of object, these can apply inherently or intentionally.When these figures and structure during through the visual field of detection system, they will provide characteristic signal, and by being only applicable to discern the electronic signal process system of relevant signal especially, each structure and figure from identify the structure that might exist and the figure.For example, this can be used for seeking the object with the invisible signalment of naked eyes, and it can be used for representing according to a certain criterion the feature of one group of object, or the like.Another purposes is to check object that one stack features is arranged, and these features guarantee that object is genuine, for example government bond and stock, banknote, other security and similar thing.

For example, object can comprise the distinctive structure of different materials, and for example this structure is included in the certain depth of object (as in semiconductor material).By using said method, the temperature variation of these enclose patterns may appear reflecting exactly from the teeth outwards.Just can check them that the form of standard is arranged by signal processing system then.If object comprises the invisible well-regulated and distinctive mass change in surface, hole for example, snotter and analog, the well-regulated variation of thickness, the watermark in the paper for example, the distinctive figure and the structure that include chemical property for example have the tangible wave spectrum of analogs such as being arranged in literal, picture to absorb the coloring matter of line, are suitable for equally.Pass through the well-regulated and distinctive structure discussed here in Xu Shu all situations, by in one side of object thermal excitation, detect the heat radiation that is produced on one side from the same one side or the opposite of object, the present invention just can be used for recognition object, the characteristic of check object and/or evaluation object.

At last, be stressed that the present invention is based on exciting and utilizing of instantaneous heat wave, but its mode was never verified in the past.As top narration, to this, necessary condition is, heat shock rises and the visual field of detection system all have with respect to object be higher than Speed of diffusion u(d) the relative velocity corresponding to instantaneous τ, given as formula (13).At this instantaneous τ, reached about 1/3 of its maximum heat drift value leaving the hot wave surface of thermal excitation apart from d.Respectively about thermal time constant τ and Speed of diffusion u(d) relational expression (12) and (13) itself be unessential.Because thermal diffusion is a random process, u(d) all can not give accurate qualification with τ.So for many application of the present invention, reach according to temperature drift be lower than its time of peaked 1/3 and stipulate a higher u(d) value is good because this heat that helps to improve between adjacent structure is spent this.In other cases, heat detected be deferred to temperature drift always to reach near it peaked 100% be more rational, Here it is provides more powerful thermal signal.So corresponding Speed of diffusion will be regarded as a lower speed.The selection of narrating as the front of being done has in this respect determined u(d basically) boundary, and the limit of speed of related movement had direct influence.Thereby must be according to here about u(d) content said of boundary removes to understand foregoing.So, the extreme value of relative velocity get approximate value degree of approximation must with definition u(d) for the degree of approximation of approximate value is the same, have one with the top corresponding to tolerance limit that is suitable for reality.In many situations, only problem is the u(d that can calculate from formula (13)) little correction on the numeral of value.When for enforcement design apparatus of the present invention, the simplest disposal route of content recited above is, narrated as the front, by stipulating u(d like that like an elephant formula (13)) and by selecting the time delay δ τ between thermal excitation and detection more greater or lesser than the τ of formula (12) lining.Be also noted that object is the situation of porous, this means that thermal excitation will be than running through deeplyer in corresponding homogeneous material, simultaneously, heat radiation can betide than in the darker level of the object of being expected in the superincumbent analysis.

These two kinds of effects will more help to improve apparent Speed of diffusion.

List of references

(1) Nuo Daoer, P.-E and Keynes spy, S.O.,＜Acta Physica Sinica 〉

20 659（1979）

(2) rein in the Hunter, E., Kroes Bill, R and Ha Di, J.D.,＜applied physiology magazine 〉

12 177（1958）

(3) Luo Senweige A and Ge Xiao, A., J.＜applied physics〉47 64(1976)

(4) Nuo Daoer, P.-E. and Keynes spy, S.O.,＜applied physics wall bulletin 〉

38 486（1981）

(5) Nuo Daoer, P.-E. and Keynes spy, S.O.,＜scanning image microscopy〉(E, A Xi edits), the 341st page. academic press, London (1980)

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Claims (28)

1, the temperature by in object, applying variation and detect the thermal-radiating variation of consequent object and characterize the performance of material, material and object and/or the method for check material, material and object, it is characterized in that, between the heat exciter of object and outside, provide a relative motion, and this excitation is continuous and preferably constant in time.And it is to put on the object along the form by continuous heating of the approach that relative motion was limited of object or cooling with a kind of, and, at object be used to measure between the visual field of detection system of the thermal-radiating variation of object that is produced a relative motion is provided, and object to the speed of related movement of detection system visual field and external heat excitation than the available heat rate of propagation height in the object, and preferably much higher.

2, in accordance with the method for claim 1, it is characterized in that available heat rate of propagation u(d) determine by following formula:

u(d)= (π ²k)/(d) ,

Wherein k is the thermal diffusion coefficient of object materials, and d represents by the physical dimension of structure, length and/or the thickness of characteristic features and/or the object that is verified.

3, according to claim 1 or 2 described methods, it is characterized in that object is with respect to the movement velocity V of detection system visual field ₂Be such, it makes satisfies relational expression

(V ₂)/(d) ＜f＜ (V ₂)/(g)

All frequency f all drop in the frequency span of detection system, wherein D and G represent respectively by the maximal value and the minimum value of structure, length or the width of characteristic features and/or the object that is verified.

According to each described method in the claim 1 to 3, it is characterized in that 4, thermal excitation is to realize with the Mechanical Contact between heating or the cooling device by object.

5, according to each described method in the claim 1 to 3, it is characterized in that thermal excitation realizes by hot gas or cold air.

6, according to each described method in the claim 1 to 3, it is characterized in that thermal excitation realizes by flame.

According to each described method in the claim 1 to 3, it is characterized in that 7, thermal excitation is ultrasonic realization that is absorbed by the component of object by being suitable for.

According to each described method in the claim 1 to 3, it is characterized in that 8, thermal excitation realizes by electron beam or other particles.

According to each described method in the claim 1 to 3, it is characterized in that 9, thermal excitation is to be chosen in and can be realized by the electromagnetic radiation of compositions of matter absorption region by wave spectrum.

10, according to the device of each described method in the claim 1 to 9, comprise object is made the device of thermal excitation and is applicable to the detection system of the thermal-radiating variation of this object that measurement produces, it is characterized in that, have way that a relative motion is provided respectively between heat exciter, detection system and object, described exciting bank is suitable for transmitting continuous thermal excitation.

According to the described device of claim 10, it is characterized in that 11, the approach along described relative motion between exciting bank and detection system has a spacing.

12, according to claim 10 or 11 described devices, it is characterized in that telecontrol equipment is suitable for guaranteeing object of which movement, and exciting bank and detection system are static substantially separately.

According to claim 10,11 or 12 described devices, it is characterized in that 13, telecontrol equipment is suitable for guaranteeing that object has identical speed of related movement to exciting bank and detection system.

According to each the described device in the claim 10 to 13, it is characterized in that 14, exciting bank is suitable for applying thermal excitation in a side (front) of object, and detection system is suitable for measuring the heat radiation that produces from the same side of object.

According to each the described device in the claim 10 to 13, it is characterized in that 15, exciting bank is suitable for applying thermal excitation in a side (front) of object, and detection system is suitable for measuring the heat radiation that the opposite side (back side) from object produces.

16, according to each the described device in the claim 10 to 15, it is characterized in that the distance L between the visual field of heat exciter and detection system is fixed, and by:

L＝v·St

Provide, wherein St＞0.5d ²/ (π ²K) and v＞u(d).

17, according to each the described device in the claim 10 to 15, it is characterized in that the distance L between the visual field of heat exciter and detection system is according to relational expression

L＝L ₀+L ₁·F（wt）

Variable, L wherein ₀=vSt, and St＞0.5d/(π ²K) and v＞u(d), L ₁＜L.And F(wt) be the one-period function, its amplitude equals 1 and angular frequency w satisfies

w＜ 1/(L ₁) -（v-u（d））

18, according to each described structure and/or the object of figure or device of product that is used to possess well-regulated and distinctive physics and/or chemical property in the claim 10 to 17, it is characterized in that it comprises an electrical signal processing system that is applicable to the corresponding regular and distinctive thermal signal that identification produces when working as described structure through the visual field of detection system.

According to each the described device in the claim 10 to 18, it is characterized in that 19, detection system comprises that one is used to limit the wave spectrum scope of heat detection and distinguish the spectral filter that is put on the electromagnetic radiation of object by heat exciter.

According to each described device in the claim 10 to 19, it is characterized in that 20, detection system comprises and being positioned at along isolated at least two detecting devices of the approach of described relative motion.

21, according to the described device of claim 20, thereby it is characterized in that one of them detecting device is positioned at described heat exciter front record from not by the signal of the object of thermal excitation, described signal is as reference signal.

22, according to each the described device in the claim 10 to 21, it is characterized in that exciting bank is suitable for carrying on object in a space orientation of determining of crosscut direction of motion the discrete electromagnetic beam of two or more different wave lengths, and detection system comprises the corresponding discrete detecting device that is used for each wavelength.

23, according to each the described device in the claim 10 to 22, it is characterized in that, exciting bank is applicable to be carried parallel with this approach or first excitation that overlaps and second excitation that has nothing to do with first excitation, and detection system comprises each other corresponding first and second detecting device, an excitation in two excitations is the mode that adopts heating, and the mode of cooling is then adopted in another excitation.

24, according to each the described device in the claim 10 to 23, it is characterized in that, except being used to detect the detecting device of the radiation that produces by described excitation, also provide a detecting device to be used for along a nearby heat radiation of approach inspected object that is parallel to exciting pathway at least, the signal that obtains from described at least one detecting device is used as reference signal.

25, according to each the described device in the claim 10 to 24, it is characterized in that, mode of motion be suitable for providing one can periodically variable speed of related movement.

26, the product that detects according to the described method of claim 1 to 9, it is characterized in that it possesses and shows and be suitable for making the well-regulated and distinctive physics of the feature that detects and/or the structure and/or the figure of chemical property on respect to the motion of the position that thermal excitation and detection take place respectively at continuous thermal excitation and this product.

According to the described product of claim 26, it is characterized in that 27, described regular and its specific structure and/or figure are the variation of local material thickness, material and/or quality.

According to claim 26 or 27 described products, it is characterized in that 28, described regular and peculiar structure and/or figure are included in has chemical substance strong and significant wave spectrum absorption line in the part electromagnetic wave spectrum.

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