CN1710412A - Method for detecting substance content and component - Google Patents

Abstract

A method for detecting composition and content ( CAC ) of material includes obtaining electromagnetic property ( EP ) of different reference material by utilizing scan measurement under different temperature and setting up databank for it ; designing circuit enabling to interact with material to be identified and obtaining its EP ; setting up EP model to know its relation to material CAC ; interacting circuit with material to be identified and solving Maxwell equation set to know relation of material and electromagnetic field for obtaining CAC of material to be identified .

Description

A kind of material composition and content detecting method

Technical field

The present invention relates to the application of a kind of electromagnetic wave spectrum technology on recognition material composition and content.

Background technology

At present, the common method of recognition material composition and content has: atomic emissions or absorption spectroscopy, x ray fluorescence spectrometry, ultraviolet or visible absorption spectrum method, fluorescence and phosphorescence spectroscopy, infra-red sepectrometry, Raman spectroscopy and nuclear magnetic resonance spectroscopy etc.The element and the content thereof of position of spectral line that the energy level transition of atomic emission spectrometry detection excited atom or ion is sent and intensity identification component; Atomic absorption spectrography (AAS) detects resonance absorption wavelength and the decay recognition element and the content thereof of excited atom; The x ray fluorescence spectrometry principle is the material that is subjected to X ray, energetic particle beam or synchrotron radiation source irradiation, the inner electron of its atom is evicted from, the emission characteristic X ray, element and the content thereof of discerning component by the wavelength and the intensity of detected characteristics X ray; Ultraviolet or visible absorption spectrum method are that the wavelength and the intensity of the absorption spectrum that produces of the variation by electron level in the detection molecules is come recognition material and content thereof; Fluorescence and phosphorescence spectroscopy are that ground state molecule absorption luminous energy is excited to be in excited state, the wavelength and the intensity of spectral line was come recognition material and content thereof when excited state was returned ground state by detecting; Infra-red sepectrometry is the interaction by relative vibration between the intramolecule atom of infrared light and detected material, and monitoring infrared Absorption wavelength and intensity are come recognition material and content thereof; Raman spectroscopy is based on the interatomic relative vibration of intramolecule of detected material to exciting scattering of light, causes that the variation of scattered light frequency comes recognition material; Nuclear magnetic resonance spectroscopy by detection be identified material in static magnetic field the Rameau precession and recognition material.The characteristics of these recognition methodss are that spectral line purity is high and stable, thereby identification easily.

Publication number is that (application number: Chinese patent application 02107199.3) discloses a kind of " resonance device; particularly microwave resonance device and measurement mechanism " to CN1375694A, system relates to a kind of resonance device, particularly a kind ofly be used to detect the microwave resonance device that there is at least a foreign matter in a kind of logistics of the tobacco industry and/or is used to measure quality, density and/or the humidity of this logistics, it comprises the hole of passing through of a resonator housing and this logistics.In addition, this invention relates to a kind of corresponding measurement mechanism and a measuring system and a method that is used to detect this logistics.The feature of this invention is that this resonance device comprises that at least one increases the element of electromagnetic wave energy density.The feature of this invention measurement mechanism is, this measurement mechanism comprises at least two resonator housings, and their determine a measurement range respectively, and wherein electromagnetic field comprises electric field, and these electric fields are being orientated in different mutually direction in spaces in corresponding measurement range.Being characterized as of this invention measuring system is provided with two devices at least, can measure logistics in different mutually direction in spaces with them.Described method can be used for detecting quality, density or the humidity that there is at least a foreign matter in a kind of logistics of the tobacco industry or is used to measure this logistics, but this method is not considered the relaxation behavior of material, can not the recognition material composition.

Summary of the invention

The purpose of this invention is to provide a kind of method of new recognition material, a kind of ONLINE RECOGNITION material composition and content detecting method based on the material relaxation behavior especially is provided.

The present invention utilizes the relaxation phenomena (or orientation polarization phenomenon or polar molecule rotation phenomenon) in the added-time power transformation magnetic field outside of polar material molecule, parameters such as relaxation time by frequency sweep method measurement of species and resonance frequency deviation, on the standard substance electromagnetic property model basis of having set up, handle composition and the content that obtains being identified material by related algorithm.

Simply introduce polar material electromagnetic property model below and based on the method and the step of material relaxation behavior recognition material.

Recognition methods based on the material relaxation behavior of the present invention is as follows:

Theoretical and the 0nsager model according to Debye, the available following The Representation Equation of the complex permittivity ε of polar material (ω):

$\mathrm{\ϵ}\left(\mathrm{\ω}\right)={\mathrm{\ϵ}}^{\′}-{\mathrm{j\ϵ}}^{\′\′}={\mathrm{\ϵ}}_{\∞}+\frac{{\mathrm{\ϵ}}_s-{\mathrm{\ϵ}}_{\∞}}{1-\mathrm{j\ω\τ}}$

${\mathrm{\ϵ}}^{\′}={\mathrm{\ϵ}}_{\∞}+\frac{{\mathrm{\ϵ}}_s-{\mathrm{\ϵ}}_{\∞}}{1+{\mathrm{\ω}}^2{\mathrm{\τ}}^2},$ ${\mathrm{\ϵ}}^{\′\′}=\frac{({\mathrm{\ϵ}}_s-{\mathrm{\ϵ}}_{\∞})\mathrm{\ω\τ}}{1+{\mathrm{\ω}}^2{\mathrm{\τ}}^2}$

$\frac{3({\mathrm{\&epsiv;}}_s-{\mathrm{\&epsiv;}}_{\&infin;})(2{\mathrm{\&epsiv;}}_s+{\mathrm{\&epsiv;}}_{\&infin;})}{{\mathrm{\&epsiv;}}_s{({\mathrm{\&epsiv;}}_{\&infin;}+2)}^2}T=\mathrm{<figure-callout\; id="2"\; label="N\; P\; m"\; filenames="A20041004002700083.png"\; state="\{\{state\}\}">N</figure-callout>}\frac{{P_m}^{}}{}\frac{{{}_{}}^2}{3{\mathrm{\&epsiv;}}_0{K}_B}$

N＝N ₀exp(-U/K _BT)

τ＝τ ₀exp(-W/K _BT)

In the following formula, ε _∞Relative dielectric constant during for infinitely great frequency; ε _sRelative dielectric constant during for zero-frequency; τ is the relaxation time; P _mDipole moment for single dipole; N is the dipole subnumber in the unit volume; ε ₀Be the specific inductive capacity in the vacuum; K _BBe Boltzmann constant; U is the dipole potential energy; W is a barrier height.

For liquid, the relaxation time computing formula of dipole molecule is:

$\mathrm{\&tau;}=\frac{4\mathrm{\&pi;}{r}^3\mathrm{\&eta;}}{K_{B}T}\mathrm{fC}$

In the following formula, f is and rotates the relevant friction factor of molecular shape; C rotates the intercouple radius factor of degree of molecule and its surrounding environment for expression; T is a temperature; K _BBe Boltzmann constant; η is a viscosity.

Known by above analysis: the DIELECTRIC CONSTANT of material (ω) is relevant with temperature T; Relaxation time τ is relevant with substance classes.From the application number of same inventor application is that known metering circuit frequency deviation Δ f and decay can obtain the flow of material and the relation of its composition volume ratio 021250715 the method.So by setting up the relation of relaxation time τ, temperature T, frequency deviation Δ f and decay, use the material electromagnetic wave spectrum characteristic that records based on the frequency sweep method, but after signal Processing the composition of recognition material and measure its content.

Material composition of the present invention and content detecting method are made up of following steps:

One, under different temperatures, different standard substances is carried out sweep measurement in advance, obtain its electromagnetic property, different standard substances is carried out sweep measurement respectively, set up the standard substance database;

Two, design a kind of can with the circuit that is identified matter interaction, measure or obtain the electromagnetic property that is identified material by the frequency sweep method;

Three, set up compounding substances electromagnetic property model, obtain the relation of material composition and content and its electromagnetic property model;

Four, make and be identified material and circuit and interact, by finding the solution the Maxwell system of equations under the specific border condition, obtain the relation of electromagnetic field and material, thereby obtain being identified the composition and the content of material.

Above-mentioned electromagnetic property mainly is the relaxation behavior of complex permittivity and complex permeability, especially material, or claims the orientation polarization loss characteristic of dipole, as complex permittivity ε (ω) and the ε that introduces previously _s, ε _∞, the isoparametric relation of T, τ; Circuit described in the step () is lumped-parameter circuit or distributed constant circuit, a kind of specifically tunable broad band circuit; Be identified the multi resonant phenomenon of shaking can take place when material and described circuit interact, thereby produce the absorption peak of a plurality of resonance absorbing peak, especially microwave, millimeter wave and submillimeter wave frequency range, can measure or obtain the electromagnetic property that is identified material by the frequency sweep method; Described sweep measurement is existing sweep measurement; The described electromagnetic property model of setting up is to adopt electromagnetic property parameters such as the resonance frequency that obtains, resonant bandwidth and resonance absorption peak, sets up the relation of electromagnetic property parameter and material composition and content with prior art.To be identified the material electromagnetic property relevant with temperature because this frequency sweep method obtains, so must constant temperature during measurement or carry out the temperature correction.Accuracy of identification and compounding substances electromagnetic property model are closely related, improve material electromagnetic property model and can improve accuracy of identification.

Method of the present invention is a kind of Non-Destructive Testing, does not promptly destroy the composition and the content of material; And be quick detection of dynamic, after promptly being identified material and circuit and interacting, obtain the result and only need several milliseconds.The inventive method recognition material good stability, precision height, energy ONLINE RECOGNITION material composition and content, applied widely.

Experimental result is as follows:

The DIELECTRIC CONSTANT of measured matter under experiment condition shown in Figure 1 _γ', ε _γ" and frequency deviation Δ f ₁, resonance frequency f ₁With the pass of standing-wave ratio (SWR) ρ be:

${{\mathrm{\&epsiv;}}_{\mathrm{\&gamma;}}}^{\&prime;}=1+2\left(\frac{{\mathrm{\&Delta;f}}_1}{f_1}\right)\&CenterDot;\frac{\mathrm{la}}{\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="2"\; label="d\; s"\; filenames="A20041004002700083.png"\; state="\{\{state\}\}">d</figure-callout>}}_s}^2}$

${{\mathrm{\&epsiv;}}_{\mathrm{\&gamma;}}}^{\&prime;\&prime;}=\mathrm{\&Delta;}\left(\frac{1}{Q_L}\right)\&CenterDot;\frac{\mathrm{la}}{\mathrm{\&pi;}{{\mathrm{<figure-callout\; id="2"\; label="d\; s"\; filenames="A20041004002700083.png"\; state="\{\{state\}\}">d</figure-callout>}}_s}^2}$

$\mathrm{\&Delta;}\left(\frac{1}{Q_L}\right)=\frac{1}{Q_L}-\frac{1}{Q_0}$

$Q_L=\frac{f_1}{{\mathrm{\&Delta;f}}_1},$ $Q_0=\frac{({\mathrm{\&rho;}}_1+1)({\mathrm{\&rho;}}_2+1)Q_L}{({\mathrm{\&rho;}}_1{\mathrm{\&rho;}}_2-1)}$

In the following formula, ds is sample hose diameter (3mm); A * b * l is the wide * height * length of cavity, is 22.86 * 10.16 * 100 (mm under this experiment condition ³); f ₁Resonance frequency for cavity; Δ f ₁Three dB bandwidth during for cavity resonant; ρ ₁The standing-wave ratio (SWR) of input end when being cavity output termination matched load; ρ ₂The standing-wave ratio (SWR) of output terminal when being cavity input termination matched load.

Under experiment condition shown in Figure 1, measure the relaxation time τ of water and the relation of temperature T and see Table 1; The relaxation time τ of several materials sees Table 2.

The relaxation time τ of table 1 water and the relation of temperature T

??T(℃)	??10	??20	??30	??40	??50	??60	??70	??80
									??τ(ps)	??11.701	??9.131	??7.084	??5.710	??4.710	??3.761	??3.240	??2.681

The relaxation time τ of several materials of table 2 (25 ℃)

Material τ	Water beetle aldehyde formic acid acetaldehyde propionic aldehyde butyraldehyde methyl acetate 9.13 6.91 8.54 29.51 6.94 7.14 8.12
		Material τ	Formamide acetic anhydride 7.29 17.98

Description of drawings

Fig. 1 is an experiment condition provided by the invention.

Fig. 2 is the system chart among the embodiment.

Fig. 3 is the circuit block diagram among the embodiment.

Embodiment

According to top method and step, this professional those of ordinary skill just can be implemented the technology of the present invention, realizes goal of the invention.

As shown in Figure 2, present embodiment comprises a circuit and matter interaction district, impedance transformer, detecting device, sweep generator and data handling system.The circuit of the present invention's design can be a lumped-parameter circuit, also can be distributed constant circuit.The present invention obtains the electromagnetic property that is identified material by the frequency sweep method, on the standard substance electromagnetic property model based of having set up, by the composition and the content of related algorithm identification measured matter.As test the result and partly introduce ε _γ', ε _γ" and ρ ₁, ρ ₂, f ₁, Δ f ₁With the isoparametric relation of ds.

The inventive method step is as follows: as shown in Figure 3, data handling system 12 control A/D converters 1 output simulation sweep voltage, simulation sweep voltage drive pressure controlled oscillator 2 output frequency sweep microwaves, the frequency sweep microwave enters microwave circuit 5 through isolator 3 and impedance transformer 4.In microwave circuit, be identified material and microwave circuit interaction in the sample hose 6, change the parameters such as resonance frequency, amplitude and bandwidth of microwave circuit, carry the microwave that is identified material property and enter detecting device 10 through impedance transformer 8 and isolator 9, detecting device output enters data handling system 12 through D/A converter 11.Data handling system compares information and the standard substance Database Systems 13 that obtain, and gets final product the composition and the content of recognition material.7 is temperature measuring circuit, is used to revise the variation that causes measurement parameter owing to temperature variation.

Above embodiment only is further described invention, and scope of the present invention is not subjected to the limitation of electromagnetic property model and algorithm in the illustrated embodiment.

Claims (6)

1, a kind of material composition and content detecting method is characterized in that being made up of following steps:

(1), under different temperatures, different standard substances is carried out sweep measurement in advance, obtain its electromagnetic property, different standard substances is carried out sweep measurement respectively, set up the standard substance database;

(2), design a kind of can with the circuit that is identified matter interaction, measure or obtain the electromagnetic property that is identified material by the frequency sweep method;

(3), set up compounding substances electromagnetic property model, the relation of acquisition material composition and content and its electromagnetic property model;

(4), make and be identified material and circuit and interact, by finding the solution the Maxwell system of equations under the specific border condition, obtain the relation of electromagnetic field and material, thereby obtain being identified the composition and the content of material.

2,, it is characterized in that described electromagnetic property is complex permittivity and complex permeability according to the described detection method of claim 1.

3,, it is characterized in that described electromagnetic property is the relaxation behavior of material according to the described detection method of claim 2.

4,, it is characterized in that the described circuit described in the step () is lumped-parameter circuit or distributed constant circuit according to the described detection method of claim 1.

5,, it is characterized in that described circuit is the tunable broad band circuit according to the described detection method of claim 4.

6, according to the described detection method of claim 1, constant temperature or carry out the temperature correction when it is characterized in that measuring.

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