JPH0484744A - Apparatus for high-speed, highly accurate quantitative analysis - Google Patents

Abstract

PURPOSE:To make it possible to perform analysis at a high speed with high accuracy by detecting the characteristic X rays of one element through a plurality of channels, and converting the detected signals obtained in the respective channels into the determined quantity values with the respective calibration curves. CONSTITUTION:The X rays which are excited with an electron beam D and emitted from a sample S are detected with a plurality of channels which are arranged around the sample S. The respective detected signals are processed in an operating device E. In the device E, the signals are converted into the determined quantity values through the respective channels with the calibration curve. The determined quantity values in the respective channels are averaged. The determined quantity value of the measured element is displayed on a display device C. Thus, the analysis is performed at a high speed in high accuracy.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to an apparatus that performs quantitative analysis with high precision and at high speed using EPMA or the like.

[Conventional technology]

If it is desired to perform quantitative analysis by X-ray spectroscopy with high precision using EPMA or the like, the analysis takes time because the integration time, that is, the measurement time must be long. On the other hand, when you want to analyze a large number of samples at high speed for quality control on a material production line, etc., there is a problem that measurement accuracy decreases because the integration time becomes shorter. Moreover, there was no equipment that could perform quantitative analysis with high precision.

[Problem to be solved by the invention]

An object of the present invention is to enable quantitative analysis to be performed at high speed and with high accuracy.

[Means to solve the problem]

In an X-ray analyzer in which the spectrometer and detector are one channel and multiple channels are installed, the multiple channels detect the characteristic X-rays of one element, and the detection signals obtained from each channel are Convert the calibration curve in the channel into a quantitative value, and install a calculation device that calculates a highly accurate quantitative value from the converted quantitative value.

[For use]

Characteristic X-rays emitted from a sample excited by electrons are emitted in all directions, and there is no need to spectrally analyze only the X-rays emitted in a specific direction. There is no problem in detecting characteristic X-rays of the same wavelength using many spectrometers from various directions. Therefore, a multi-channel spectrometer equipped with a large number of spectrometers has been proposed, but in conventional multi-channel spectrometers, each spectrometer is set to a wavelength corresponding to a different element, and the same element can be detected in many ways. It was not measured using a spectrometer. The present invention detects characteristic X-rays with wavelengths corresponding to the same element using multiple spectrometers, obtains quantitative values from the detection signals obtained from each detector, and selects the most probable quantitative value from each quantitative value. By calculating this, it is possible to obtain highly accurate quantitative values comparable to the required integration time in a short time.

【Example】

In Figure 0, which shows an embodiment of the present invention, S is a sample, which is excited by an electron beam and emits X-rays. channels (a set consisting of one spectrometer and one detector)
The X-rays corresponding to the same element are
Detection is performed on all channels, and the obtained detection signal is converted into a quantitative value (concentration) using a calibration curve for each channel in the calculation device E, and the quantitative values of each channel are averaged to determine the measured element. The quantitative value is determined, and the determined quantitative value is displayed on the display device C.
Display in . The spectrometers and detectors installed in each channel do not have the same combinations of spectroscopic crystals and detection elements, and it is better to have different combinations of spectroscopic crystals and detection elements.
The channel spectroscopic crystal is LiF, the detection element is ADP, the second channel spectroscopic crystal is LiF, the detection element is PET,
The third channel spectroscopic crystal is RAP, and the detection element is Pb5.
T, the X-rays are combined for each channel, and for the same element, not only the same characteristic X-rays but also characteristic X-rays of different wavelengths such as Kα rays and Lα rays are used. With a set of spectroscopic crystals, X-ray detection elements, and detected X-ray wavelengths, the quantitative values of actual samples with different compositions of coexisting elements show slight deviations from the calibration curves made from standard samples, and there is also a backlash. The influence of ground and noise differs depending on the spectroscopic crystal, detector, and detection wavelength, so if you use various combinations of spectroscopic crystals, detectors, and detection wavelengths, these effects will be averaged, and a single combination The accuracy is better than in the case of . In the above example, the concentration value of the measured element was obtained by simply averaging the quantitative values of each channel. However, depending on the channel, due to a setting error or trouble, the quantitative value may show a value that is different from other quantitative values (abnormal value). There are cases. In such a case, it is better to exclude the abnormal values and average the remaining normal values. This method, which is an example of a method for obtaining highly accurate quantitative values from quantitative values, is based on the idea that the frequency of appearance of measured values is closer to the true measured value, the higher the density is.
In other words, the measured value for which the largest number of other measured values are within the specified error range is the closest to the true measured value, and this embodiment attempts to search for such a measured value. be. Specifically, when the tolerance value ±ε corresponding to the desired accuracy is set and the quantitative value of each channel is set as Wi (i = 1 to n), each quantitative value is set as the reference value for each channel. , compare the difference between the quantitative value of other channels and the reference value with the above tolerance value ε, count the channels whose quantitative value is smaller than the tolerance value ε, and calculate the channel whose counted value is the maximum. A reference value (constant, quantitative value) is determined as the element concentration of the sample to be sought. If there are multiple channels with the maximum count value, the average value of the quantitative values of those channels is determined as the element concentration of the sample to be determined. Measured values that deviate greatly from the direct value appear less frequently, so
In the case of decimal measurements, such measurements occur only about once on either side. In simple averaging, such measured values are also included in the average calculation, so the average value will be biased towards measured values that deviate significantly from the direct value. In this embodiment, such a problem is avoided, and a measured value closer to a direct value than a simple average is obtained.

【effect】

According to the present invention, a characteristic X of one element can be obtained using multiple spectrometers.
By spectroscopy of the lines, it is now possible to obtain the quantitative value of the integration time to obtain the desired accuracy by dividing the measurement into multiple channels, allowing for fast and highly accurate quantitative analysis. It became possible.

[Brief explanation of drawings]

The figure is a configuration diagram of an embodiment of the present invention.

Claims (2)

[Claims] (1) In an X-ray analyzer with a single channel spectrometer and a detector, and multiple channels installed, multiple channels detect characteristic X-rays of one element, and the detection obtained with each channel A high-speed, high-precision quantitative analyzer characterized by being equipped with an arithmetic device that converts signals into quantitative values using a calibration curve in each channel and averages the converted quantitative values. (2) In an X-ray analyzer with a single channel spectrometer and a detector, and multiple channels installed, multiple channels detect characteristic X-rays of one element, and the detection obtained with each channel Convert the signal into a quantitative value using the calibration curve in each channel, and sequentially designate one of all the converted quantitative values as the reference quantitative value, and select the other values for which the difference between the specified quantitative values is within the tolerance value. A high-speed, high-precision quantitative analyzer, characterized in that it is equipped with a calculation device that counts the number of quantitative value channels and sets the quantitative value of the channel with the largest counted value as the measured value.