SU1074827A1 - Method and device for determining coordinates of photometering points - Google Patents

Description

The invention relates to spectral analysis and can be used for automated processing of photospectrograms of mass emission analysis in geochemical and similar types of research. Spectrographs are recorded on spectrographs for emission analysis. The scale of the recording of the spectrum is not identical for spectrographs of even one brand, and may also be not strictly linear. The degree of nonlinearity is usually unknown. To interpret the results of the emission analysis, it is necessary to characterize the spectrum given a quantization step. In addition, each fragment of the spectrum is characterized by the intensity of the light flux passing through this fragment, and the fragment coordinate (wavelength. Registration of these data In the volume of several thousand numbers for each spectrum, automatic microphotometers are used.A well-known method for determining the coordinates of photometric points involves linear movement of a carriage with a spectrogram, measured by the angle of rotation of the micrometric screw. The method is carried out by a device containing an illuminator, a carriage for placing a photo-spectrogram, a photometric channel, an encoder, a memory block, a coordinate sensor in the form of of the minimum screw that moves the carriage, the synchronic with radial gaps, and the photodiode cell, which fixes the rotation angle of the synchrodisk and the spectrometer traveled, your first distance. The encoder is triggered from the photodiode, which fixes the rotation of the synchrodisk, and the resolution to write the encoded information to the memory unit comes from the second photochannel, which analyzes the reference plate with labels corresponding to the region of the desired spectral lines on the spectrogram under study. One of the indicated photochannels studies one of the spectrograms, the one under study, and the other is standard ETjj. The disadvantages of the known method and device are the low accuracy of determining the coordinates jf in the well-known instrument of 30 µm with reference to the nearest spectral line of a known wavelength, and the difference in real scale on the reference spectrogram with the labels and on the photographic program under investigation due to the nonidentity of the spectrographs for emission analysis. This prevents the memory unit from starting up in time and registering the required part of the spectrum; therefore, in practice, the entire spectrum is encoded and the memory unit is launched using a coordinate sensor. The closest to the invention according to the technical nature is a method for determining the coordinates of photometric points and a device for determining the coordinates of photometric points. The method includes photometry of the scanned spectrogram with quantization jaw & , identification of the reference lines of the spectrum and the definition of the desired coordinates. The device contains a carriage, its displacement system, an illuminator, a photometric channel connected to the encoder input, an encoder trigger unit from a coordinate sensor as a set of diffraction gratings and a photodiode, and a memory block 2. A disadvantage of the known method and device is the low accuracy of determining coordinates waves) due to the variable scale of the registration of the spectrum by the spectrograph. The aim of the invention is to improve the accuracy of determining the coordinates. The goal is achieved by the fact that according to the method, which includes photometry of the scanned spectrogram with a quantization step and, identification of reference spectral lines and determining the desired coordinates from them, photometry is performed simultaneously in X and :. 2 points spaced along the scanning direction at a distance LK, the magnitude of which is not less than the quantization step D and i is greater than the minimum distance between the two reference lines, and the coordinates of the spectral lines are determined from the ratio n p 1, where 1 + 1) is the number of the reference the line nearest to the desired coordinate I, whose coordinate is Yar. satisfies the condition i p -i 9, the coordinate of the reference spectral line, closest to the desired coordinate, which satisfies the condition I. (, is the number of integer intervals of length L1 /. between the coordinates Yar and fi,

N;, / - number of quantum-steps steps -v 1 .l

neither in 1 + 1 interval of length L J,;

j is the number of integer intervals of length L between the coordinates Yar IAR4 (, is the number of steps quantum neither between the beginning of J + 1 interval of length LJJ and the coordinate L pii /

N;, j is the number of quanto steps. vani in the J + 1 interval of length Ljj.

A device for determining the coordinates of the photometric points containing the carriage, its moving system, the illuminator, the photometric channel connected to the input of the encoder, the starting block of the encoder and the memory block are equipped with one or more additional photometric channels, while the optical axes of all channels are parallel and are located in a plane intersecting the spectrum under investigation along a straight line parallel to its length of the axial axis, and the channel outputs are connected to the encoder input.

FIG. 1 shows a flow chart of the method; in fig. 2 scheme of the proposed device.

As a result of simultaneous photometry and spectrum coding at several points with a given quantization step, the measurement results are accumulated in the form of several arrays, one for each of the indicated points. The array element characterizing the intensity of the stream passing through the same fragment of the spectrum is shifted by approximately to numbers, where IY is the distance between the optical axes of any pair of photo channels; U is the coordinate quantization step.

Determining the coordinates of photometric points 1-5 of FIG. 1) as follows. It was established experimentally that the spectrum of any sample has clearly identifiable (reference) iron lines located on a photographic plate with a pitch of about 20 mm and having a known wavelength. In addition, there are about 1-2 thousand characteristics in the spectrum, easily identifiable lines or their combinations, located on a photospectrogram at a distance of about 20-100 microns (at wavelengths of the spectrum).

The first group of reference lines is used in the algorithm below to assign the elements of an array of a discretized spectrum to exact coordinates, the second group of characteristic lines is for ident.

, fikatsii elements in two arrays and precise coordinates,

Choose in one array a portion of the sampled spectrum between the two reference lines. RJJ and Rp with known wavelengths of Ap, p-ti- / IP cFig. one). In the second array in the region shifted by N elements, we will find, for example, the correlation analysis of the elements Rp and

  characterizing the same fragments of the spectrum as Rp and. Since the quantization step and the number of the elements of the arrays corresponding to the reference lines Kp, Rpt, R, R, etc. ,

5 are approximately known, the identification of the reference line is simple. It is currently used in the processing of photospectrograms encoded on known microphotometers. Element

0 1 in the first array is measured simultaneously with the RP of the second array, therefore, the distance between elements by Rp- and 1 (the spectrum is L with a precision of no worse than 0.5 and. Continuing this operation, we divide the spectrum between RP and (j parts , length Lt and one part length, g

where is the number of quantization steps in

Q j + 1-th interval of length LK, including Rp,, is the step number in j) + 1st interval on which the line Rp + i- is encountered. From here, Lj can be determined for each array; real-time recording of the spectra: grams in the interval from Rp dpRp4 for example, by the formula

4-U,., ()

and the coordinate f, of any point of photometry in this range is, for example, by the formula

| ..; IL., (2)

(3)

l

1mT 5

where i is the number of integer intervals of length L1 between Rp and the study fragment of a photospectrogram;

N is the number of quantization steps

- and in the i + 1 interval of length L, including a point with coordinate 1;

5 p; j- NUMBER of quantization steps from

the beginning of +1 interval length L 1 to the point with coordinate 1

It is possible to increase the accuracy of calculations, using data from several arrays, i.e. photometry of the studied spectrum at several points simultaneously. This allows reducing the amount of recorded data, if in the spectrum

Claims (1)

(57) 1. A method for determining the coordinates of photometry points, including photometry of a scanned spectrogram with a quantization step ή, identification of the reference lines of the spectrum and determination of the desired coordinates from them, characterized in that, in order to improve the accuracy of determining coordinates, photometry is performed simultaneously in k 1 2 points spaced along the scanning direction at a distance Lfc, the values of which are not less than the quantization step D and not more than the minimum distance between two Reference lines, and the coordinates are spectral lines C x is determined from the relation