JPS63243853A - Automatic qualitative analysis instrument - Google Patents

Abstract

PURPOSE:To make exacter automatic decision by a computer by executing processing by using the spectrum information on a standard sample obtd. under the same acceleration voltage conditions as the conditions at the time of the analysis as reference data. CONSTITUTION:A sample S is excited by an excitation ray E and the characteristic X-rays released from the sample S are spectrally split by a spectroscope 1. The X-rays spectrally split by the spectroscope 1 are detected and processed in a signal measuring part 3. A CPU 4 outputs the control signal for driving the spectroscope 1 to a prescribed wavelength to a spectroscope driving part 2, stores the measurement data obtd. in the signal measuring part 3 in a data memory device 7, and makes element decision by subjecting the measurement data stored in the memory device 7 to a comparison operation by the decision program stored in a decision program memory device 6 in accordance with the reference data previously stored in the data memory device 7. More specifically, the measurement data is processed by the decision program stored in the decision program storage device 6 in accordance with the spectrum information of the standard sample obtd. under the same acceleration voltage conditions as the conditions at the time of the analysis as the reference data, by which the automatic analysis of the unknown sample is executed.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Field of Industrial Application The present invention is used to excite a sample with charged particles such as an X-ray microanalyzer (EPMA) and measure and determine the characteristic X-ray spectrum emitted from the surface of the excited sample. The present invention relates to an apparatus for automatically qualitatively analyzing elements contained in a sample.

B. Prior art In recent years, analysis of measurement data obtained by EPMA and the like has come to be automatically performed by computer. The conventional method for analyzing characteristic X-ray spectra using a computer is to compare and examine the measurement data obtained through measurement using a fixed determination program based on the fixed group zP: data pre-installed in the computer to determine the element. Is going. However, the characteristic X-rays emitted from the excited sample surface include -characteristic X-rays emitted from the I element; The characteristic X-rays generated by the transition of electrons from the outer shell to the vacancies in the shell are U, M, ... rays. A large number of characteristic X-rays are generated, and when multiple elements are present, these characteristic X-rays or their higher-order diffraction lines appear close to each other or appear superimposed. It is necessary to determine which characteristic X-ray of which element the detected peak corresponds to. However, X-ray spectrometers have wavelength errors that change over time, and when making a judgment about a single peak, the range of elements that must be considered varies depending on the target of analysis and the purpose of analysis.

For this reason, the judgment criteria and programs sometimes need to be modified, but in conventional automatic qualitative analyzers, the judgment programs are fixed and cannot be changed depending on the sample, so the judgment must be made by a skilled analyst. There is a problem that the accuracy is inferior compared to the case.

C1 Problems to be Solved by the Invention The present invention aims to enable more accurate automatic determination by computer in elemental determination in qualitative analysis of EPMA.

21 Means for Solving Problems In an apparatus that excites a sample with an excitation line and performs automatic qualitative analysis of the sample using radiation emitted from the sample, a means for storing data and a standard stored in the data storage means are provided. Judgment program storage means for storing a program for automatically qualitatively analyzing an unknown sample by analyzing measurement data based on the data; means for changing the judgment order or judgment criteria of the program stored in the judgment program storage means; and a judgment program. A data processing means is provided for automatically analyzing unknown samples by processing measurement data using a determination program stored in a storage device and using spectral information of a standard sample obtained at the same acceleration voltage CF as that used for analysis as reference data. .

3-Effect In element determination in qualitative analysis of EPMA, the measurement data used for automatic determination includes wavelength errors specific to the device. By using the measured data, the reference data includes the same wavelength error as during measurement, and even if a low-precision spectrometer is used, no wavelength shift occurs between the measured data and the reference data. These features make it possible to perform automatic qualitative analysis with high accuracy using an inexpensive spectrometer.

In addition, in the judgment method, the judgment accuracy is improved by changing the identification order of contained elements and judgment criteria depending on the sample, so the judgment accuracy can be improved by making it possible to change the program stored in the judgment program storage device for each sample. The aim is to measure the improvement of

Embodiment FIG. 1 shows an embodiment of the present invention.
is a sample, E is an excitation line that excites the sample S, 1 is a spectrometer that spectrally spectra the characteristic X-rays emitted from the excited sample S, 2
is a spectrometer drive unit that drives the spectrometer 1 to a predetermined wavelength position, 3 is a signal measurement unit that detects and processes the X-rays separated by the spectrometer 1, and 4 is a spectrometer drive unit 2 in which the spectrometer 1 is specified. It outputs a control signal for driving to the wavelength of , stores the measurement data obtained by the signal measurement section 3 in the data storage bag W7, and stores the measurement data stored in the data storage device 7 in the data storage device 7 in advance. The CPU is a CPU that performs element determination by performing comparison calculations using a determination program stored in the determination program storage device 6 based on the reference data obtained.

Reference numeral 5 denotes an operating device for instructing the CPU/4, changing the determination program, and inputting data to the data storage device. 8 is a display device that displays the results obtained by the CPU 4.

In the above configuration, the present invention will be explained in detail.

Standard samples are sequentially measured and reference data as shown in the table below is stored in the data storage device for each element.

Fe element spectrum list spectrometer Valence Wavelength (person) Signal strength Chi
FeKβ(n-1) 1.757 200F
eK α (n:I) 1. 937 1
000FeKβ (n=2) 3.514 30C
h2 FeKα (n:2) 3.8.74 10
0FeKβ(n-3) 3.514 25Ch3
・・・・・・・・・・・・・・・・・・・・
・ ・ ・・・・・・ ・・ ・・ ・F e
L β (n-1) 17. 255 30
0FeKα(n・9) ], 7.433 3
0 With these standard data, the characteristic X-ray wavelength is not the theoretical value, but the displayed wavelength of the spectrometer, and the displayed wavelength includes the wavelength error of spectrometer 1, so the theoretical value is It's different.

Next, the measurement sample is set and measured, and the obtained measurement data is used to determine the elements contained in the sample in accordance with the flowchart shown in FIG. 2 based on the reference data stored in the data storage device 7. Perform identification.

Specify the elements to be identified first in order of priority (a)
. AKβ/AKα=N of each designated element A and its allowable error Δ are input using the operating device 5 (a). Calculate AKβ/AKα value of specified element A from measurement data (1)
, AKβ/AKα value is N-Δ≦AKβ/AKα≦N+Δ
(1). If satisfied, it is determined that the sample contains element A (e), and the signal intensity corresponding to the data of element A included in the characteristic X-ray wavelength value of element A is subtracted from the measurement data (e). ). motion(
If the question conditions in 1) are not satisfied, the peak is considered undetermined and the operation jumps to (g). Next, it is determined whether the next-ranked element to be identified exists (K). If it exists, return to operation (1) and repeat the following operations. If it does not exist, exit.

Action (a) is described so that it must be specified each time, but
Perform input operations only when changing the stored logic program. If not changed, the stored value shall be used.

Calibration measurements for measuring the above standard samples are performed from time to time, and if the reference data obtained in the measurement differs from the reference data stored in the data storage device, the reference data stored in the data storage device is Replace with the reference data obtained by measurement. This ensures that the reference data stored in the data storage device always matches the wavelength of the current spectrometer. In addition, by gradually increasing the variety of standard samples, it is possible to enrich the standard data held.

Since the signal strength changes depending on the accelerating voltage, it is necessary to perform all measurements under a constant accelerating voltage or to obtain reference data for each accelerating voltage. However, since there is a proportional relationship between the current value of the irradiation beam and the X-ray intensity,
When analysis is performed based on the signal strength ratio of each valence of the line, the current value may be set to a value of II-I. Qualitative analysis is performed using the reference data obtained as described above.

By using the data obtained with the same device to determine the best measured spectrum for the unknown sample t1, unlike the case of using ready-made theoretical and ideal spectrometer data such as wavelength tables, , equipment constants, etc. are canceled out and much more accurate results are obtained.

G. Effects According to the present invention, wavelength errors no longer occur even when using an inexpensive spectrometer that is not very accurate, and the judgment order or judgment criteria in the judgment program can be changed arbitrarily. It has become possible to significantly improve the accuracy of automatic qualitative analysis with low accuracy.

[Brief explanation of drawings]

FIG. 1 is a block diagram of an embodiment of the present invention, and FIG. 2 is a flowchart of a determination program. S...sample, E...excitation line, 1 ・X-ray spectrometer, 2
... Spectrometer drive section, 3 - Signal measurement section, 4... CP
[J, 5... Operating device, 6... Judgment program storage device, 7. Data storage device, 8... Display device.

Claims (1)

[Claims] In an apparatus that excites a sample with an excitation ray and performs automatic qualitative analysis of the sample using X-rays emitted from the sample, the measured data is analyzed using a data storage means and reference data stored in the data storage means. Judgment program storage means for storing a program for automatic qualitative analysis of unknown samples; means for changing the judgment order or judgment criteria of the programs stored in the judgment program storage means; and a judgment program stored in the judgment program storage device. An automatic qualitative analysis device characterized in that it is equipped with a data processing means for automatically analyzing an unknown sample by processing the spectrum information of a standard sample obtained under the same accelerating voltage conditions as when analyzing the measured data as reference data. .