JPS61724A - Removal of back ground of spctrum and its apparatus - Google Patents

Abstract

PURPOSE:To increase processing speeds of qualitative and quantitative analyses, by obtaining a spectrum deprived of its background. CONSTITUTION:As a background intensity of a dividing point a5 is lower than those of a4, a6, the intensity of spectrum of the point a5 is defined as the background intensity. Respecting the background intensity of the point a15, as the spectrum intensity of the division point a14 is low, and that of the point a16 is high, the mean value of the spectrum intensities of a14 and a15 is defined as the background intensity. This maintains not only a macroscopic shape covering an extensive area, but prevent it from exceeding the corresponding original spectrum intensity. Backgrounds of each division point a1-an obtained by a intensity discriminator 8 are compensated with an interpolating appartus 9 with a straight line or a quadratic curve between respective division points and moothened with a smoothening apparatus. Subtracting this value from the original spectrum with a differential apparatus, display can be made by a display apparatus.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention is applicable to, for example, E S CA ("E 1 electro
n S spectroscopy for Ch.
The present invention relates to a method and an apparatus for removing background from an obtained spectrum in an analyzer such as an analyzer (e.g., an analyzer) that can obtain a spectrum with a background.

<Prior Art> Conventionally, when measuring a wide spectrum in which a plurality of peaks exist, the peaks appear on top of the background. Therefore, when performing quantitative analysis,
As shown in the fourth curve, a narrow area scan is performed, a straight line is drawn as a background so as to touch the background on both sides, and the peak intensity or area intensity is determined for the peak above this straight line. However, with such conventional background removal methods, narrow peaks must be measured individually, which is time-consuming.Furthermore, since the background is treated as a straight line and removed in each narrow range, it is necessary to measure a wide range of peaks. The physics that the curved background is originally
There were drawbacks such as the background removal method ignoring chemical meaning.

<Problems to be Solved by the Invention> The present invention has been made in view of the above points, and aims to increase the speed of analytical processing such as quantitative determination by obtaining a spectrum from which background has been removed. shall be.

<Means for Solving the Problems> In order to achieve the above-mentioned object, the present invention divides a spectrum obtained by wide-area measurement into equal intervals with a width that allows each peak constituting the spectrum to be divided. The background intensity of each dividing point is calculated based on the spectral intensity of each dividing point and the dividing points on both sides of it.
The obtained background intensity is subtracted from the spectrum to remove the background.

The present invention also provides a means for storing a spectrum obtained by wide-area measurement, a means for setting the number of division points for dividing the spectrum, and a method for storing the spectrum in the storage means based on the output from the setting means. means for extracting and storing the spectral intensity of each division point from the spectrum stored in the extraction storage means, and extracting and storing the background intensity of each division point from the spectral intensity stored in the extraction storage means, means for calculating and determining based on the spectral intensities of division points of the determination means; means for interpolating background intensities between division points based on the background intensities from the determination means; and a spectrum stored in the storage means. and means for subtracting the background intensity interpolated by the interpolation means from the spectral background removing device.

<Example> Hereinafter, an example of the present invention will be described in detail with reference to the drawings. This embodiment will be explained in a manner applicable to ESCA.

FIG. 1 is a block diagram of one embodiment of the present invention. The electrons energy-analyzed by the analyzer 1 are detected by the detector 2, further amplified by the amplifier 3, and provided to the spectrum background removing device 4.

Spectral background removal device 4 of this embodiment
The system includes a scaler 5 as a means for storing the spectrum shown in FIG. 2 measured over a wide energy range by the analyzer 1, and a division point setting device 6 for setting the number of division points for dividing the spectrum. , a division extractor 7 as a means for extracting and storing the spectrum intensity of each division point a1 to an from the spectrum stored in the scaler 5 based on the output from the division point number setting device 6; Each dividing point a1 to an
The background intensity of is calculated for each division point a1 to an,
an intensity determiner 8 as means for calculating and determining based on the spectral intensities of each division point and the division points on both sides thereof;
An interpolator 9 as a means for interpolating the background intensity between dividing points based on the background intensity from the intensity determiner 8, a smoother 10 for smoothing the background curve between the dividing points, and a scaler. It includes a subtractor 11 as a means for subtracting the background intensity interpolated by an interpolator 9 and further smoothed by a smoother 10 from the spectrum stored in the spectrum stored in the spectrometer 5, and a display 12. The smoothing point number setter 13 is used to set the roughness of the smoothing interval between division points, and is appropriately selected depending on the properties of the spectrum.

In the spectral background removal method of the present invention,
First, the spectrum shown in the second figure obtained by wide-area measurement is divided into equal intervals with a width that allows each peak constituting the spectrum to be divided. This division point setting is performed by a division point setting device 6. The division extractor 7 extracts and stores the intensity of each division point al' to an of the spectrum using the scaler 5 in response to the output of the division point number setter 6.

Next, the background intensity of each of the divided division points a1 to an is determined for each division point a1 to 1l11 based on the spectral intensity of each division point and the division points on both sides thereof. Calculation of this background intensity is performed by the intensity determiner 8 as follows.

That is, for example, the background intensity of division point a2 is the same as that of division point a2 and its neighboring division points a1. ．． The background intensity of the dividing point a14 is determined based on a3.
It is determined based on the division points ai 3 , al 4 , and al5. In this example, if the spectral intensity of the central dividing point is lower than the spectral intensities of the dividing points on both sides, the spectral intensity of the central dividing point is set as the background'intensity; otherwise, ( When the spectral intensity of the central dividing point is higher than the spectral intensity of the dividing points on both sides, or when the spectral intensity of one of the adjacent dividing points is lower than the spectral intensity of the central dividing point and the other spectral intensity is at the center. 2) whose spectral intensity is lower than the spectral intensity of the dividing point
The average spectral intensity of the two division points is taken as the background intensity.

For example, the background intensity of division point a5 is the same as that of division point a4 on both sides of it. Since the spectral intensity of a6 is higher than the spectral intensity of the central dividing point a5, the dividing point ', L5
The spectral intensity of is taken as the background intensity. Furthermore, the background intensity of the dividing point a15 is the same as that of the dividing points al4. One dividing point a14 among al 6
Since the spectral intensity of the other dividing point a16 is lower than that of dividing point a15, and the spectral intensity of the other dividing point a16 is higher than that of dividing point a15, the average value of the spectral intensities of dividing point a14 and dividing point a15 is set as the background intensity.

The purpose of determining the background intensity in this way is to maintain the macroscopic shape over a wide range of the original spectrum and to avoid losing the physical and chemical meaning of the background of the original spectrum. , 1 to prevent the suppressed background intensity from becoming higher than the intensity of the corresponding original spectrum.

The background intensities of the dividing points a1 to an obtained by the intensity determiner 8 are supplemented by straight lines or quadratic curves between the dividing points by the interpolator 9, and then smoothed by the smoother 10.

Next, the obtained background intensity is subtracted from the original spectrum by the subtractor 11, and the spectrum shown in the third figure from which the background has been removed is obtained on the display 12.

<Effects of the Invention> As described above, according to the present invention, a wide spectrum without background can be obtained, so there is no need to perform a narrow scan to remove the background as in the prior art, and qualitative and quantitative Improves analysis processing speed. Furthermore, according to the present invention, it is possible to obtain a difference spectrum consisting of a collection of peaks that have physical and chemical meaning.

[Brief explanation of the drawing]

FIG. 1 is a block diagram of an embodiment of the present invention, FIG. 2 is a block diagram, and FIG. 4 is a spectrum for explaining a conventional example. 4...spectral background removal device, 5.
... Scaler, 6... Division point setter, 7... Division extractor, 8... Strength judger, 9... Interpolator, 11.
...Differentiator.

Claims (2)

[Claims] (1) Divide the spectrum obtained by wide-area measurement into equal intervals with a width that allows each peak constituting the spectrum to be divided, and calculate the background intensity at each division point for each division point. 1. A method for removing a background in a spectrum, characterized in that the background is removed by obtaining the spectral intensity of a dividing point and the dividing points on both sides of the dividing point, and subtracting the obtained background intensity from the spectrum. (2) means for storing a spectrum obtained by wide-area measurement; means for setting the number of division points for dividing the spectrum; and a spectrum stored in the storage means based on the output from the setting means. means for extracting and storing the spectral intensity of each division point from the extraction storage means; and extracting and storing the background intensity of each division point from the spectral intensity stored in the extraction and storage means, means for calculating and determining based on the spectral intensity of the determining means; means for interpolating the background intensity between division points based on the background intensity from the determining means; and means for subtracting the background intensity interpolated by the means.