WO2012027867A1

WO2012027867A1 - Online spectrum analyzer for detecting diffuse reflection with ultraviolet (uv), visible and near infrared (nir) light

Info

Publication number: WO2012027867A1
Application number: PCT/CN2010/001602
Authority: WO
Inventors: 丁峰; 刘混海; 李志伟; 周峰; 杜伟
Original assignee: 南通北极光自动控制技术有限公司
Priority date: 2010-08-30
Filing date: 2010-10-13
Publication date: 2012-03-08
Also published as: CN101922969A

Abstract

An online spectrum analyzer for detecting diffuse reflection with UV, visible and NIR light includes a housing, inside which an illuminating system, a probe, an optical splitting system, a signal acquiring system, a calibrating system and a spectrum processing system are provided. The illuminating system, the signal acquiring system, the calibrating system and the spectrum processing system are all together connected to a power supply system. The illuminating system is used to emit the light rays of UV, visible and NIR waveband to illuminate the detected object. The probe is used to collect the light rays diffuse-reflected by the detected object, and transmit the collected light rays to the optical splitting system. The light rays are split by a grating to form light rays with different wavebands. The signal acquiring system converts the optical signal into digital signal and collects the digital signal. The spectrum calibrated by the calibrating system is sent to the spectrum processing system to be processed, analyzed and displayed so that the detection result is determined.

Description

Ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectroscopy

The invention relates to an ultraviolet, visible and near infrared on-line detection diffuse reflectance spectrum analyzer for the analysis of liquid, solid and high light scattering liquids.

Background technique:

Spectroscopic instruments are instruments for spectroscopy and material spectroscopy. They are widely used in various optical detection and biochemical analysis by measuring the spectrum of light, measuring the optical properties of materials and identifying the composition of materials. , industrial automation testing, astronomical research and other fields.

Ultraviolet (UV) refers to electromagnetic waves with a wavelength in the range of 185 to 400 nm, which cannot be perceived by the human eye. Because the electronic spectrum of most molecules is in the ultraviolet region, and the electronic spectrum of the molecule can basically determine the chemical reaction of the molecule, the molecular spectroscopy can be used to perform molecular qualitative analysis, quantitative analysis, structural analysis, and molecular chemical reactions. Spectral technology work.

Visible (VIS) refers to electromagnetic waves with a wavelength in the range of 380 to 780 nm, which can be perceived by the human eye. Visible light is the most widely used band and is closely related to people's lives. With visible light, analysis of light components, measurement and calculation of color, measurement of material properties, and molecular spectral analysis can be achieved.

Near Infrared (NIR) is an electromagnetic wave between visible light (VIS) and mid-infrared light (MIR), that is, electromagnetic waves with a wavelength in the range of 780 to 2500 nm, which are not perceptible by the human eye. It is customary to divide the near-infrared region into near-infrared short-wave and near-infrared long-spectral regions; around 1900, near-infrared (NIR) spectroscopy instruments use glass prisms and film recorders, and their spectral range is limited to 700 nm-1600 nm. The frequency doubling and combined frequency absorption signals of the material in this spectral region are weak, the bands overlap, and the analysis is complicated. Due to the technical level at that time, the near-infrared spectrum "sleeps" for nearly one and a half centuries. It was only in the 1950s that near-infrared spectroscopy was applied to the analysis of agricultural and sideline products. In the 1950s, the near-infrared (NIR) spectrometer used a lead sulfide photoresistor as a detector. The wavelength range was up to 3000 nm for quantification. Analysis, but due to the low resolution of near-infrared light (NIR) extinction coefficient and spectral bandwidth, this technique has not been widely used. In the 1960s, diffuse reflectance technology was used to study the moisture, protein and fat content of wheat, and found near-infrared. The useful value of light (NIR) spectroscopy for routine analysis. With the development of computers and the birth of chemometrics, the combination of near-infrared light (NIR) and chemometrics has produced modern near-infrared (NIR) spectroscopy. Near-infrared light (NIR) was first used in agriculture. In the mid-to-late 60s, with the emergence of various new analytical techniques, coupled with the weak sensitivity and poor anti-interference weakness exposed by classical NIR spectroscopy, people have indifferent to the application of this technology in analytical testing. The near-infrared spectrum entered a period of silence. In the late 1980s, with the rapid development of computer technology, the development of digitization and chemometrics of analytical instruments, the good results achieved by chemometric methods in solving spectral information extraction and background interference, and the near-infrared spectroscopy were measured. The unique characteristics of the technology make people re-recognize the value of near-infrared spectroscopy, and the application research of near-infrared spectroscopy in various fields has been launched. In the 1990s, the application of near-infrared spectroscopy in the industrial field was fully developed. The research and application literature on near-infrared spectroscopy almost expanded exponentially, becoming the fastest growing and most compelling independent analysis technology. Due to the good transmission characteristics of near-infrared light in conventional optical fibers, NIR spectroscopy has also been well applied in the field of online analysis, and has achieved good social and economic benefits. From then on, near-infrared spectroscopy technology has entered a rapidly developing In the new era, modern near-infrared spectroscopy (NIR) analysis technology is a high-tech analytical technology that has developed rapidly in the field of analytical chemistry in recent years. It has attracted more and more attention from domestic and foreign analytical experts. It is known as the analysis of "giant" in the field of analytical chemistry. There is a revolution that can be said to bring another analytical technique.

Summary of the invention: The object of the present invention is to overcome the above deficiencies, and to provide an ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer with wide application fields and accurate measurement.

The object of the present invention is achieved by the following technical solutions: an ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer, comprising a housing, an illumination system, a probe, an optical spectroscopic system, a signal acquisition system, and a housing inside the housing, The calibration system and the spectral processing system, the illumination system, the signal acquisition system, the calibration system, and the spectral processing system are connected together with a power supply system, and the illumination system is used to emit ultraviolet, visible, and near-infrared light, illuminate the object to be measured, and the probe is used. Collecting the diffused light of the measured object and transmitting the collected light to the optical splitting system. The optical splitting system uses the grating to split the light into different wavelengths of light, and the signal acquisition system converts the optical signal into a digital signal and collects the light. By correcting the corrected spectrum of the system, it is processed, analyzed and displayed by the spectral processing system to determine the detection result.

A further improvement of the present invention is that the probe includes a scope and an optical fiber, and the scope of the probe is used to expand the lighting area to allow more light to enter the spectroscopic system, and the optical fiber is used to transmit the optical signal.

A further improvement of the present invention resides in that: the main component of the optical splitting system is a grating, and the optical splitting system uses light splitting of the grating to disperse light into light of different wavelengths.

A further improvement of the present invention is: the signal acquisition system comprises a receiving unit, an amplifying unit and an collecting unit, the receiving unit is configured to transmit the weak electrical signal converted into the received optical signal to the amplifying unit, and the amplifying unit is configured to receive the receiving unit The transmitted weak electrical signal is amplified to the extent that it can be acquired, and the acquisition unit is used to convert an electrical signal that is not recognized by the computer, that is, an analog signal, into a digital signal that can be recognized by the computer.

A further improvement of the present invention is that the correction system includes a distance sensor for measuring the distance between the object to be measured and the temperature sensor, and a temperature sensor for measuring the temperature of the object to be measured. The one-step improvement of the present invention is: the spectral processing system includes a processing module and an analysis module, and the processing module includes a pre-processing section for pre-processing the acquired spectral signal to reduce high-frequency noise in the spectrum and improve The digital low-pass filter with spectral signal-to-noise ratio, because the distance and temperature of the measured object will affect the reflected light intensity, the distance and temperature signals obtained by the correction system are substituted into the relationship between the distance and temperature obtained by the prior experiment on the light intensity. In the function part, to reduce the influence of the distance and temperature changes on the reflected light intensity, the analysis module includes a mathematical model of a function part obtained by a large number of preliminary tests for a certain substance, and the preprocessed spectral signal is passed. After the model is calculated, the content of a specific substance can be obtained.

A further improvement of the present invention is that: the light source is irradiated onto the object to be measured, and after the light interacts with the object to be measured, the diffuse reflection light is generated, collected by the probe in the probe and transmitted through the optical fiber in the probe, by the optical After the spectroscopic system splits the light, it is collected by the signal acquisition system, and the spectrum corrected by the calibration system is sent to the spectral processing system for qualitative and quantitative analysis of the spectral processing, thereby determining the detection result.

Compared with the prior art, the invention has the following advantages: wide application field, accurate measurement, and can be used for measurement in various industries.

BRIEF DESCRIPTION OF THE DRAWINGS:

Figure 1 is a schematic structural view of the present invention;

detailed description:

The present invention will be further described in detail with reference to the embodiments of the present invention, which are intended to be illustrative only, and not to limit the scope of the invention.

The present invention shows an embodiment of an ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer, the spectrum analyzer comprising a housing, an illumination system, a probe, an optical spectroscopic system, and a signal acquisition system , calibration systems and spectral processing systems, lighting systems, signal acquisition systems The system, the calibration system and the spectral processing system are connected to a power supply system. The illumination system is used to emit ultraviolet, visible, and near-infrared light, illuminate the object to be measured, and the probe is used to collect the light after the object is diffusely reflected, and will collect The latter light is transmitted to the optical splitting system. The optical splitting system uses the grating to split the light into different wavelengths of light, converts the optical signal into a digital signal through a signal acquisition system, and performs acquisition, and corrects the corrected spectrum of the system and gives it to the spectral processing. The system processes, analyzes, and displays to determine the test results, and the measurement range is wide. The probe includes a probe and an optical fiber. The probe is used to expand the light-recovering area to allow more light to enter the spectroscopic system. The optical fiber is used to transmit optical signals. The main component of the spectroscopic system is a grating. The optical spectroscopic system uses the spectroscopic action of the grating to disperse the light into different wavelengths of light. The signal acquisition system comprises a receiving unit, an amplifying unit and an acquisition unit, and the receiving unit is configured to convert the received optical signal into Weak electrical signal is transmitted to the amplification list The amplifying unit is configured to amplify the weak electrical signal sent by the receiving unit to a degree that can be collected, and the collecting unit converts the electrical signal that the computer cannot recognize, that is, the analog signal into a digital signal that can be recognized by the computer, and the calibration system includes the distance sensor and the temperature. The sensor, the distance sensor is used to measure the distance between the measured object and the probe, the temperature sensor is used to measure the temperature of the measured object, the spectral processing system comprises a processing module and an analysis module, and the processing module comprises a pre-preparation of the acquired spectral signal. The pre-processing part of the processing, the digital low-pass filter used to reduce the high-frequency noise in the spectrum and improve the spectral signal-to-noise ratio. Since the distance and temperature of the measured object affect the reflected light intensity, the distance obtained by the correction system is The temperature signal is substituted into the function part of the relationship between the distance and temperature obtained by the prior experiment on the light intensity, to reduce the influence of the distance and temperature change on the reflected light intensity, and the analysis module includes a large amount of The function part obtained in the previous experiment is the mathematical model, which will preprocess the light. After the spectrum signal is calculated by the model, the content of the specific substance can be obtained, and the content of the specific substance can be obtained. Unlike the conventional analysis technology, the near-infrared spectrum is an indirect analysis technique, and the mathematical model must be established to realize the identification of the unknown sample. Or quantitative analysis, mainly through the following Steps: First select a representative sample and measure its near-infrared spectrum, use standard or approved reference methods to determine the component or property data of interest, and use the appropriate stoichiometry to establish a mathematical model using the measured spectra and basic data. To determine the composition or properties of the unknown sample, the analyzer of the present invention is irradiated onto the object to be measured by the light source, and the light interacts with the object to be measured to generate diffuse light, which is reflected by the probe. Collecting and transmitting through the optical fiber in the probe, after being split by the optical spectroscopic system, collecting by the signal acquisition system, correcting the corrected spectrum of the system, and handing it to the spectral processing system for qualitative and quantitative analysis of the spectral processing, thereby determining Test results, can be used in petroleum and petrochemical, basic organic chemicals, fine chemicals, metallurgy, life sciences, pharmaceuticals, medical clinical, agriculture, food, beverage, tobacco, textile, paper, cosmetics, quality supervision, environmental protection, universities and research Institutes, etc., in the petrochemical field, the oil can be measured Value, family composition, hexadecimal value, flash point, freezing point, freezing point, distillation range, MTBE content, etc. In the agricultural field, the protein, sugar, fat, fiber, moisture content, etc. of the grain can be determined, and the medicine can be determined in the medicine field. The active ingredient, composition and content can also be used to identify the type of sample, such as the true and false identification of alcohol and perfume, the classification of environmental waste, etc., the analysis of this ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer The test results are more accurate, and there is no damage to the measured object, no need to pre-process, so the measurement is relatively simple.

Claims

Rights request

1. An ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer, characterized in that: the spectrum analyzer comprises a casing, and the casing is internally provided with an illumination system, a probe, an optical spectroscopic system, and a signal acquisition system. And a calibration system and a spectral processing system, wherein the illumination system, the signal acquisition system, the calibration system, and the spectral processing system are connected to a power supply system, and the illumination system is configured to emit ultraviolet, visible, and near-infrared light, and illuminate the measured object. The probe is configured to collect the diffused light of the measured object, and transmit the collected light to the optical splitting system. The optical splitting system uses the grating to split the light into different wavelengths of light, and the signal acquisition system converts the optical signal into The digital signal is collected and corrected by the calibration system, and then processed, analyzed and displayed by the spectral processing system to determine the detection result.

2. The ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer according to claim 1, wherein: the probe comprises a probe and an optical fiber, and the probe is used to expand the light-receiving area to make more light. Entering the splitting system, the fiber is used to transmit optical signals.

3. The ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer according to claim 1, wherein: the main component of the optical spectroscopic system is a grating, and the optical spectroscopic system uses light splitting of the grating to disperse the light. Light into different wavelengths.

4. The ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer according to claim 1, wherein: the signal acquisition system comprises a receiving unit, an amplifying unit and an acquiring unit, and the receiving unit is configured to receive the The weak electrical signal converted into the optical signal is transmitted to the amplifying unit, and the amplifying unit is configured to amplify the weak electrical signal sent by the receiving unit to a degree that can be collected; the collecting unit is configured to use an electrical signal that is not recognized by the computer. The analog signal is converted into a digital signal that the computer can recognize.

5. Ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectroscopy according to claim 1. The calibration system includes: a distance sensor for measuring a distance between the measured object and the probe, and a temperature sensor for measuring a temperature of the measured object.

6. The ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer according to claim 1, wherein: said spectral processing system comprises a processing module and an analysis module, said processing module comprising spectral signals for collecting Pre-processing part for pre-processing, digital low-pass filter for reducing high-frequency noise in the spectrum and improving spectral signal-to-noise ratio. Since the distance and temperature of the measured object affect the reflected light intensity, the correction system is obtained. The distance and temperature signals are substituted into the function portion of the relationship between the distance and the temperature-affected relationship of the light intensity obtained by the prior experiment to reduce the influence of the distance and the temperature change on the reflected light intensity, and the analysis module includes The function is obtained by a large number of preliminary experiments, that is, the mathematical model. After the pre-processed spectral signal is calculated by the model, the content of the specific substance can be obtained. The analysis module is obtained by a large number of preliminary tests for a certain substance. Mathematical model, after the pre-processed spectral signal is calculated by the model, Content of specific substances.

7. The ultraviolet, visible, near-infrared on-line detection diffuse reflectance spectrum analyzer according to claim 1, wherein the light source is irradiated onto the object to be measured, and the light interacts with the object to be measured to generate diffuse reflection light. Collected by the probe in the probe and transmitted through the optical fiber in the probe, after being split by the optical splitting system, collected by the signal acquisition system, and the spectrum corrected by the calibration system is sent to the spectral processing system for spectral processing. Qualitative and quantitative analysis to determine the test results.