阅读说明：本技术 一种光谱仪输出光谱补偿方法 (Spectrum output compensation method for spectrometer ) 是由 张国宏 李光尧 闫晓剑 刘浩 于 2019-10-21 设计创作，主要内容包括：本发明涉及光谱仪补偿校准技术,其公开了一种光谱仪输出光谱补偿方法,直接在光谱输出端进行光谱补偿,从而提高光谱仪的检测质量。本发明将光谱仪初始状态对标准漫反射样品采集获取的第一数据查询表和在修正状态下对标准漫反射样品采集获取的第二数据查询表进行对应索引位置的光强差值计算,从而获取波长、反射率和光强补偿值关系的第三数据查询表,将在光谱仪修正状态下采集的实物光强光谱作为第四数据查询表,与第二数据查询表进行比较,找到光谱仪在修正状态下的实物光谱在第二查询表中的对应位置,即数据位置索引值,通过数据位置索引值确定实物光谱在第三查询中应该补偿的差值,基于此应该补偿的差值对光谱输出进行补偿。(The invention relates to a spectrometer compensation calibration technology and discloses a spectrometer output spectrum compensation method which directly performs spectrum compensation at a spectrum output end so as to improve the detection quality of a spectrometer. The method comprises the steps of calculating the light intensity difference value of the corresponding index position of a first data query table acquired by a standard diffuse reflection sample in an initial state of a spectrometer and a second data query table acquired by the standard diffuse reflection sample in a correction state, acquiring a third data query table of the wavelength, reflectivity and light intensity compensation value relation, comparing a real object light intensity spectrum acquired in the correction state of the spectrometer with the second data query table, finding the corresponding position of the real object spectrum of the spectrometer in the second query table in the correction state, namely a data position index value, determining the difference value of the real object spectrum to be compensated in the third query through the data position index value, and compensating the spectrum output based on the difference value to be compensated.)

1. A method for compensating the output spectrum of a spectrometer, comprising the steps of:

a. in the initial state of the spectrometer, acquiring light intensity spectra of standard diffuse reflection samples with different reflectivities, and establishing a data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection samples in the initial state of the spectrometer as a first lookup table;

b. in the correction state of the spectrometer, collecting light intensity spectra of standard diffuse reflection samples with different reflectivities, and establishing a data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection samples in the correction state of the spectrometer as a second lookup table;

c. establishing a standard diffuse reflection sample light intensity, wavelength and light intensity compensation value data relation lookup table according to the first lookup table and the second lookup table to serve as a third lookup table;

d. in the correction state of the spectrometer, acquiring the output light intensity spectrum of the object to be detected to obtain the light intensity spectrum of the object in the correction state of the spectrometer, and using the light intensity spectrum as a fourth lookup table;

e. comparing the fourth lookup table with the second lookup table to determine the index position of the real object spectrum in the second lookup table in the correction state of the spectrometer, so as to search and obtain the light intensity compensation value in the third lookup table;

f. and compensating the searched light intensity compensation value to the real spectrum for output.

2. A method of compensating the output spectrum of a spectrometer as in claim 1,

the spectrometer is a diffuse reflection test type near-infrared spectrometer, and the standard diffuse reflection sample has stable reflectivity in a near-infrared band.

3. A method of compensating the output spectrum of a spectrometer as in claim 1,

in the step a, the establishing of the data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection sample in the initial state of the spectrometer specifically comprises the following steps:

the precision of the reflectivity change is set to be 0.01%, and the light intensity spectrums of the samples with different reflectivities are inserted or fitted between the output light intensity spectrums of the standard diffuse reflection samples with different reflectivities collected in the initial state of the spectrometer.

4. A method of compensating the output spectrum of a spectrometer as in claim 1,

in the step b, the establishing of the data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection sample in the correction state of the spectrometer specifically comprises the following steps:

the precision of the reflectivity change is set to be 0.01%, and the light intensity spectrums of the samples with different reflectivities are inserted or fitted between the output light intensity spectrums of the standard diffuse reflection samples with different reflectivities collected in the correction state of the spectrometer.

5. A method of compensating the output spectrum of a spectrometer as in claim 1,

in step c, the step of establishing a standard diffuse reflection sample light intensity, wavelength and light intensity compensation value data relation lookup table according to the first lookup table and the second lookup table specifically comprises the following steps:

and calculating the light intensity difference value of the two data query tables at the same index value by taking the positions of the wavelength and the reflectivity in the tables as index values, so as to establish a data relation query table of the reflectivity of the standard diffuse reflection sample, the working wavelength of the spectrometer and the light intensity compensation value in the initial and correction states of the spectrometer.

6. A method of compensating the output spectrum of a spectrometer as claimed in any of claims 1 to 5,

in step e, the comparing the fourth lookup table with the second lookup table to determine the index position of the real object spectrum in the second lookup table in the spectrometer correction state, so as to search and obtain the light intensity compensation value in the third lookup table, specifically includes:

comparing the fourth lookup table with the second lookup table, and according to the relationship among light intensity, wavelength and reflectivity coordinates, at a specified wavelength position, performing difference and sequencing on the light intensity of the spectrum in the fourth lookup table and the light intensity of the spectrum in the second lookup table to find a corresponding position of the real spectrum of the spectrometer in a corrected state in the second lookup table, namely a data position index value.

Technical Field

The invention relates to a spectrometer compensation calibration technology, in particular to a spectrometer output spectrum compensation method, which is particularly suitable for calibration and compensation of a diffuse reflection type near-infrared spectrometer.

Background

The output light intensity of a spectrometer, particularly a portable near-infrared spectrometer, can be influenced by the intensity change of a light source, the environmental change, the change of a detector and the like, so that the output spectrum of the spectrometer is changed; because the light splitting system and the detection system of the portable near infrared spectrometer are precise and complex to disassemble and assemble, the operation of compensating and calibrating various input factors from the input port of the spectrometer is troublesome, and especially in the client site, professional personnel are required to be equipped for spectrum calibration and compensation operation.

Therefore, the invention provides a method for directly performing spectrum compensation at a spectrum output end by comprehensively considering the influence of various input conditions, particularly aiming at a diffuse reflection test type spectrometer, so as to realize the output compensation of the spectrometer.

Disclosure of Invention

The technical problem to be solved by the invention is as follows: the spectrum compensation method for the output of the spectrometer is provided, and the spectrum compensation is directly carried out at the spectrum output end, so that the detection quality of the spectrometer is improved.

The technical scheme adopted by the invention for solving the technical problems is as follows:

a method of compensating for the output spectrum of a spectrometer, comprising the steps of:

a. in the initial state of the spectrometer, acquiring light intensity spectra of standard diffuse reflection samples with different reflectivities, and establishing a data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection samples in the initial state of the spectrometer as a first lookup table;

b. in the correction state of the spectrometer, collecting light intensity spectra of standard diffuse reflection samples with different reflectivities, and establishing a data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection samples in the correction state of the spectrometer as a second lookup table;

c. establishing a standard diffuse reflection sample light intensity, wavelength and light intensity compensation value data relation lookup table according to the first lookup table and the second lookup table to serve as a third lookup table;

d. in the correction state of the spectrometer, acquiring the output light intensity spectrum of the object to be detected to obtain the light intensity spectrum of the object in the correction state of the spectrometer, and using the light intensity spectrum as a fourth lookup table;

e. comparing the fourth lookup table with the second lookup table to determine the index position of the real object spectrum in the second lookup table in the correction state of the spectrometer, so as to search and obtain the light intensity compensation value in the third lookup table;

f. and compensating the searched light intensity compensation value to the real spectrum for output.

As a further optimization, the spectrometer is a diffuse reflection test type near infrared spectrometer, and the standard diffuse reflection sample has stable reflectivity in a near infrared band.

Based on the characteristic that a standard diffuse reflection sample has stable reflectivity in a near-infrared band and the light intensity output is changed only due to different reflectivities, the corresponding relation among the spectrum, the reflectivity and the wavelength of a sufficient sample can be conveniently obtained through an interpolation or data fitting mode.

As a further optimization, in step a, the establishing of the data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection sample in the initial state of the spectrometer specifically includes:

the precision of the reflectivity change is set to be 0.01%, and the light intensity spectrums of the samples with different reflectivities are inserted or fitted between the output light intensity spectrums of the standard diffuse reflection samples with different reflectivities collected in the initial state of the spectrometer.

The light intensity spectrum of a sufficient amount of other samples in the initial state of the spectrometer can be quickly obtained by means of interpolation or data fitting between the spectra of the collected samples with different reflectivities.

As a further optimization, in step b, the establishing of the data relation lookup table of the light intensity, the wavelength and the reflectivity of the standard diffuse reflection sample in the correction state of the spectrometer specifically includes:

the precision of the reflectivity change is set to be 0.01%, and the light intensity spectrums of the samples with different reflectivities are inserted or fitted between the output light intensity spectrums of the standard diffuse reflection samples with different reflectivities collected in the correction state of the spectrometer.

The light intensity spectrum of a sufficient amount of other samples in the correction state of the spectrometer can be quickly obtained by means of interpolation or data fitting between the spectra of collected samples with different reflectivities.

As a further optimization, in step c, the establishing of a standard diffuse reflection sample light intensity, wavelength and light intensity compensation value data relation lookup table according to the first lookup table and the second lookup table specifically includes:

and calculating the light intensity difference value of the two data query tables at the same index value by taking the positions of the wavelength and the reflectivity in the tables as index values, so as to establish a data relation query table of the reflectivity of the standard diffuse reflection sample, the working wavelength of the spectrometer and the light intensity compensation value in the initial and correction states of the spectrometer.

Because the first lookup table and the second lookup table have the same data structure, the output light intensity values of the same standard diffuse reflection sample at the designated wavelength point and the reflectivity can be determined according to the two factors of the wavelength and the reflectivity, and therefore the light intensity compensation values at the corresponding wavelength and reflectivity indexes in the initial state and the correction state of the spectrometer can be calculated.

As a further optimization, in step e, the comparing the fourth lookup table with the second lookup table to determine the index position of the real object spectrum in the corrected state of the spectrometer in the second lookup table, so as to find the light intensity compensation value in the third lookup table, specifically includes:

comparing the fourth lookup table with the second lookup table, and according to the relationship among light intensity, wavelength and reflectivity coordinates, at a specified wavelength position, performing difference and sequencing on the light intensity of the spectrum in the fourth lookup table and the light intensity of the spectrum in the second lookup table to find a corresponding position of the real spectrum of the spectrometer in a corrected state in the second lookup table, namely a data position index value.

The data position index value of the object spectrum in the second lookup table is determined based on the comparison between the fourth lookup table and the second lookup table, and accordingly, the data position index value can be used for quickly searching for a corresponding compensation value in a third lookup table with the same data structure as the second lookup table.

The invention has the beneficial effects that:

the method has the advantages of correcting spectral peak shift and rotation, correcting spectral change caused by spectral system attenuation and environmental change and the like, along with simple operation work of compensation and calibration, no need of professional personnel and profound significance for large-scale use of spectrometers, particularly portable spectrometers.

Drawings

FIG. 1 is a schematic diagram of the output spectrum compensation principle of the spectrometer of the present invention.

Detailed Description

The invention aims to provide a spectrum compensation method for spectrometer output, which directly performs spectrum compensation at a spectrum output end, thereby improving the detection quality of the spectrometer. The invention utilizes the characteristic that the standard diffuse reflection sample is stable in the known spectral range and the reflectivity thereof is stable in a long time, and the light intensity output is changed only by the different reflectivities, uses the corresponding relation between the standard diffuse reflection sample and the light intensity, interpolates the corresponding light intensity value among the different reflectivities, establishes three two-dimensional array data query tables of the output light intensity, the reflectivity and the wavelength point of the standard diffuse reflection sample, realizes the light intensity output compensation effect of the spectrometer through the relation of the three data query tables, and achieves the purpose of calibrating the spectrometer.

In a specific implementation, the principle of spectrum compensation output by the spectrometer in the present invention is as shown in fig. 1, a first data lookup table acquired by collecting a standard diffuse reflection sample in an initial state of the spectrometer and a second data lookup table acquired by collecting the standard diffuse reflection sample in a corrected state are subjected to light intensity difference calculation corresponding to an index position, so as to acquire a third data lookup table having a wavelength, reflectivity and light intensity compensation value relationship, a real object light intensity spectrum acquired in the corrected state of the spectrometer is used as a fourth data lookup table, and is compared with the second data lookup table, so as to find a corresponding position of the real object spectrum in the corrected state of the spectrometer in the second lookup table, that is, a data position index value, because the third lookup table and the second lookup table are the same data structure, a difference value that the real object spectrum should be compensated in the third lookup table is determined by the data position index value, the spectral output is compensated based on this difference that should be compensated.

The specific realization of the spectrometer output spectrum compensation method in the invention comprises the following steps

(1) And (3) acquiring the output spectrum of a standard diffuse reflection sample in the initial state of the spectrometer:

3 standard diffuse reflection samples (the diffuse reflection rates are 2.5%, 50% and 99%) with different reflectances in the working wavelength range of the spectrometer are subjected to spectrum collection by using a diffuse reflection type spectrometer, and a standard diffuse reflection sample output light intensity spectrum in the initial state of the spectrometer is obtained.

(2) Establishing a standard diffuse reflection sample light intensity, wavelength and reflectivity data look-up table in an initial state of the spectrometer:

setting the precision of the reflectivity change to be 0.01%, inserting or fitting the light intensity spectrums of the samples with different reflectivities between the light intensity spectrums with different reflectivities in the pair (1) in an interpolation or mathematical fitting mode, setting the state to be an initial state, obtaining a standard diffuse reflection sample light intensity, wavelength and reflectivity data query table, and obtaining a first data query table.

(3) Establishing a standard diffuse reflection sample light intensity, wavelength and reflectivity data lookup table in a spectrometer correction state

When the spectrometer works for a period of time or is influenced by changes of working environment, the output spectrum needs to be corrected or compensated, and the light intensity, wavelength and reflectivity data lookup tables of standard diffuse reflection samples with different reflectivities in the current state are interpolated or fitted by adopting the same modes in (1) and (2) to obtain a second data lookup table.

(4) Establishing a standard diffuse reflection sample wavelength, reflectivity and light intensity compensation data lookup table in the initial and correction states of the spectrometer:

and determining spectral compensation values at different data position index values through a standard diffuse reflection sample light intensity, wavelength and reflectivity data query table established in an initial and correction state to obtain a third data query table.

(5) The spectrometer collects the spectrum of the real object in a correction state:

and (3) carrying out spectrum acquisition on the object to be detected by using a spectrometer, obtaining the spectrum of the object in the correction state of the spectrometer, and obtaining a fourth data query table.

(6) And (3) detecting the spectrum of the real object by the spectrometer in the correction state to perform output compensation:

comparing the fourth table with the second table, according to the relationship among light intensity, wavelength and reflectivity coordinates, performing difference and sequencing on the light intensity of the spectrum in the fourth data query table and the light intensity of the spectrum in the second data query table at the position of the specified wavelength, finding the position (data position index value) of the real spectrum of the spectrometer in the corrected state in the second data query table, obtaining the data position index value of the real spectrum, determining the difference value which should be compensated in the third data query of the real spectrum according to the data position index value, and finally compensating the light intensity compensation value corresponding to the data position index value to the real light intensity spectrum for output.