CN103868941A - Energy dispersive X-ray fluorescence analysis rapidly judging method - Google Patents

Abstract

The invention discloses an energy dispersive X-ray fluorescence analysis rapidly judging method. In conventional X-ray fluorescence analyser analysis softwares, data acquisition process and analysis process of a sensor are separated, specifically data acquisition of a sample signal is firstly finished, acquisition time is manually set, and sample analysis is then performed after acquisition is finished. In the technical scheme, data acquisition process and element composition analysis process of a sensor are combined; according to set time steps, analysis is performed once when an time step is reached; the current result and a last analysis result are compared; the error limit and a most step number are set, if on-line analysis reaches the set error limit, sampling is finished, and if the sampling time reaches the set most step number, sampling is finished also; and the final result is subjected to once fine analysis, so as to obtain the detection result.

Description

The quick determination methods of a kind of energy-dispersive X-ray fluorescence (EDXRF) analysis

Technical field

The present invention relates to instrumental science field, is that one is carried out dynamic interpretation for X-fluorescence spectroanalysis instrument to sensing data, obtains fast suitable Measuring Time length, improves a kind of method of analysis precision.

Background technology

X-ray fluorescence spectra analysis is a kind of method for elemental analysis and chemical state research, and this research starts from the beginning of the fifties of eighties of last century, has experienced the development of six more than ten years, the very large achievement having obtained.It with to sample without advantages such as damage, non-environmental-pollutions, obtained extremely widely application in inorganic analysis fields such as geology, metallurgy, material, environment, industry and medical and health.Especially energy dispersion X-ray spectral analysis (EnergyDispersive X-Ray Fluorescence, EDXRF), have fast, accurately, economy can realize the features such as multielement analysis again, has become the most important analysis means of component analysis in various inorganic material.

In x-ray fluorescence analysis process, X-ray tube inspires X ray, be irradiated on analyzed material, and under the exciting of X ray, the high level electronics generation energy level transition of tested element atom and send secondary X-ray.Because the atomic energy level structure of each element is all specific, the energy of the X ray that it is emitted when transition after being excited is also specific, and this secondary X-ray is called characteristic X-ray.By measuring the energy of characteristic X-ray, just can determine the existence of respective element, the power of characteristic X-ray (be x-ray photon number) represents the content of this element.The collection of X ray is completed by detector.Moment detector can be realized analyzed characteristic X-ray is gathered and carries out digitized processing.Then these characteristic X-rays are counted respectively with the size of energy, different energy is digitized into the distribution address of different channel address or perhaps energy spectral line, each channel counts value is equivalent to the amplitude of spectral line, to should level x-ray photon quantity number.What therefore the passage of sensor and the count value of each passage were corresponding is the characteristic X-ray energy spectral line that a detected materials inspires.It has reflected the feature of characteristic X-ray that sensor gathers that reflexes to of material, and each spectral line represented the distribution situation of different-energy characteristic X-ray photon numbers.The peak value of each spectral line and area response the content of corresponding element in analyzed material.In actual application, in order to determine the corresponding element of spectral line peak value, need to carry out a series of processing to the spectral line obtaining, it comprises the matching of spectrum smoothing, background deduction, peak-seeking, energy calibration and characteristic spectrum, finally goes out the content of element in material according to Area Ratio.

In the analytic process of x-ray fluorescence analyzer, the acquisition time of characteristic X-ray normally rule of thumb obtains.

If Measuring Time is shorter, undesired signal can be brought considerable influence to measuring accuracy so, if Measuring Time is oversize, analysis need to take a long time and be uneconomical.If can find a kind of method, can judge online sensor data acquisition situation, performance analysis measurement result, so just can improve measuring accuracy when Measurement sensibility stops measuring process automatically, and the efficiency of analyser is improved.

Summary of the invention

The problem to be solved in the present invention is: a kind of analytical approach is provided, it is in sensor collected specimens signal, energy spectral line is carried out to online express-analysis, when finding that the result of analyzing reaches unanimity, after the analysis precision that error reaches analyser requires, stop sensor sampling immediately, then analysis result is repeatedly carried out comprehensively.Adopt and can avoid in this way Measuring Time can only lean on experience, what measurement data stability was bad determines, improves thereby reach measuring accuracy, and testing efficiency is good, the reliable object of test duration length science.

Technical scheme of the present invention is: in general x-ray fluorescence analyzer analysis software, data acquisition and the analytic process of sensor are separated, first complete the data acquisition of sample signal, acquisition time is artificially set, and carries out the analysis of sample after having gathered again.In the present invention, the data acquisition of sensor and elemental composition analytic process are combined, according to certain setting-up time step-length, every time step is just analyzed once, this result and last analysis result are compared, specification error limit and at most step-length number, if on-line analysis reaches specification error limit, sampling finishes, if sampling duration has reached maximum step-length numbers of setting, sampling also finishes.Last result is once segmented and is analysed again, thus the testing result of obtaining.Compared with prior art, advantage of the present invention is:

(1) conventionally the analysis of sensor collection signal and sensing data result separate in x-ray fluorescence analyzer, and the needed time of collected specimens signal is by experience, and the present invention has provided a kind of energy self-adaptation and obtain the rational method of minute.It combines signals collecting and signal analysis, by defining the rational limits of error and step-length number, has ensured the precision of analyzing, and also ensures to gather one and completes surely.

(2) obtain analysis result based on the present invention, have higher precision, also can be as required, set rational precision, thereby reach analysis speed faster.

(3) the control survey time that the present invention can be very intelligent.The robotization of Realization analysis and intellectuality, easy to use, energy-conserving and environment-protective.

Embodiment

X-ray fluorescence analysis is a kind of elemental analysis method based on X ray characteristic, if analyzed material is positioned over to X-tube below correct position, when X-tube is launched X ray with after certain angular illumination is on sample, under the exciting of X ray, in the time that its energy is greater than the combination energy of a certain orbital electron, this electronics can be evicted from, form hole, now, the electronics of higher energy level, by the regular transition according to certain, can produce secondary X-ray in this process.Because the atomic energy level structure of each element is all specific, the energy of the X ray that it is emitted when transition after being excited is also specific, and this secondary X-ray is called characteristic X-ray.As long as can measure the energy of characteristic X-ray, just can determine the existence of respective element, the power (being the number of x-ray photon) of characteristic X-ray represents the content of this element.The characteristic X-ray that sample excitation goes out has formed an energy spectral line, by analyzing this spectrum, just can know having or not and the number of content of element in material.

Obviously be the integral process to signal for the gatherer process of characteristic X-ray, the time is longer, and the photon numbers of collecting is more.This means that useful signal is just more intense, just higher to the analysis resolution of element.In fact inevitably there is electronic noise in sensor, line-hit, non-ideal factor in making, thereby there is noise in the signal that causes collecting, short at acquisition time, in the weak situation of signal, noise shared ratio in spectral line is just larger, and therefore the sampling time is also subject to the restriction of noise factor.But the long sampling time can cause measuring process tediously long, and analysis efficiency is low.Determining or the experience of leaning on of sampling time, is Best Times section at present, observes the variation of spectrum when operation completely with operating personnel, and the raising of accuracy of detection has been brought to impact.The solution of the present invention is as follows:

One, segmentation performance analysis

1, the gatherer process time to characteristic X-ray is divided into time step Step:

Step＝5(s)

Specify maximum step-length M.

If there is element E in sample _i, corresponding spectral line area S _i(i=1,2 ... N), the content Δ E of element _i:

$\mathrm{\Δ}{E}_i=\frac{S_i}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{S}_j}$

Instrument is δ to each elements are contained error, establishes the element number N that instrument can be analyzed, and the measuring error of establishing each element is δ _i(i=, 2 ... N), and

kδ≥δ _i

K is a coefficient, and it can obtain standard model is done to timing signal.Conventionally the analytic process of X ray comprises following measure: the matching of spectrum smoothing, background deduction, peak-seeking, energy calibration and characteristic spectrum.

2, carry out data acquisition by time step Step, the collection of characteristic X-ray is completed by detector; Once arriving a step-length, acquisition time carries out the work of step 3;

3, performance analysis, in this process, for speed up processing, it only uses the link such as matching of spectrum smoothing, background deduction, peak-seeking and characteristic spectrum to the analysis of characteristic X-ray spectral line, namely adopts the analytic process of simplifying.And calculating accordingly the area change of spectral line and the ratio of characteristic peak area, concrete corresponding what element of this characteristic peak and content do not provide immediately in this link.

4, after next time step arrives, again characteristic X-ray spectral line is carried out to performance analysis, calculate the area of spectral line and the number percent of content, by the percent delta E of each spectral line content _iwith last result of calculation Δ E ' _icontrast, whether error in judgement reaches the condition needing:

|ΔE _i-ΔE’ _i?|≤kδ

If do not reach condition, continue 2,3,4 steps, once reach condition or reached maximum step-length M, gatherer process finishes.

5, characteristic X-ray spectrum is done to further complete processing, all processes such as the matching that comprises complete spectrum smoothing, background deduction, peak-seeking, energy calibration and characteristic spectrum, and provide the content of each element by quantitative test.

Two, realize the speed that the important guarantee of the method is dynamic process and want fast, the calculating of precision simultaneously can not be affected, if adopt complete analytic process, the processing time needing is long, smoothness that can impact analysis process.In fact, in intermediate treatment process, do not need to know immediately corresponding which kind of element in spectral line characteristic peak and concrete content, only need to obtain the ratio between different characteristic peak-to-peak shape area.Meanwhile, in performance analysis, can adopt the method for partial analysis, to accelerate analysis speed.For this reason, can select only to analyze a hemichannel, only the peak-to-peak relative content of character pair be analyzed simultaneously, can accelerate like this speed of analyzing and processing.

Three, in performance analysis, the condition of having measured | Δ E _i-Δ E ' _i| also can make δ into _i, can do further requirement to measuring accuracy like this.

Claims (1)

1. the quick determination methods of energy-dispersive X-ray fluorescence (EDXRF) analysis, is characterized in that comprising the following steps:

1) the gatherer process time to characteristic X-ray is divided into time step Step:

Step＝5(s)

Specify maximum step-length M.

If there is element E in sample _i, corresponding spectral line area S _i(i=1,2 ... N), the content Δ E of element _i:

$\mathrm{\Δ}{E}_i=\frac{S_i}{\underset{j=1}{\overset{N}{\mathrm{\Σ}}}{S}_j}$

Instrument is δ to each elements are contained error, establishes the element number N that instrument can be analyzed, and the measuring error of establishing each element is δ _i(i=1,2 ... N), and

kδ≥δ _i

K is a coefficient, and it can obtain standard model is done to timing signal.Conventionally the analytic process of X ray comprises following measure: the matching of spectrum smoothing, background deduction, peak-seeking, energy calibration and characteristic spectrum.

2) carry out data acquisition by time step Step, the collection of characteristic X-ray is completed by detector; Once arriving a step-length, acquisition time carries out the work of step 3;

3) performance analysis, in this process, for speed up processing, it only uses the link such as matching of spectrum smoothing, background deduction, peak-seeking and characteristic spectrum to the analysis of characteristic X-ray spectral line, namely adopts the analytic process of simplifying.And calculating accordingly the area change of spectral line and the ratio of characteristic peak area, concrete corresponding what element of this characteristic peak and content do not provide immediately in this link.

4) after next time step arrives, again characteristic X-ray spectral line is carried out to performance analysis, calculate the area of spectral line and the number percent of content, by the percent delta E of each spectral line content _iwith last result of calculation Δ E ' _icontrast, whether error in judgement reaches the condition needing:

|ΔE _i-ΔE’ _i?|≤kδ

If do not reach condition, continue 2,3,4 steps, once reach condition or reached maximum step-length M, gatherer process finishes.

5) characteristic X-ray spectrum is done to further complete processing, all processes such as the matching that comprises complete spectrum smoothing, background deduction, peak-seeking, energy calibration and characteristic spectrum, and provide the content of each element by quantitative test.