CN108318428A - A kind of photoelectric sensing measuring device - Google Patents

Abstract

The invention belongs to the technical field of photoelectric sensing and measuring equipment, and relates to a photoelectric sensing and measuring device. A transparent window is designed on the circumference of the filter wheel, and a test light source and a photodetector are installed on the coaxial optical path corresponding to the transparent window. , used to accurately locate the wavelength, the filter wheel is combined with the light source, polarizer, lens combination, sample chamber, detector and simple mechanical support to form a photoelectric sensing and measuring device based on a wavelength-tunable light source, and the filter wheel is driven by a motor Rotate and change the optical path lens combination-the filter working in the sample chamber to accurately locate different wavelengths. The polarizer captures the polarized light in the natural light emitted by the light source and forms parallel light after the lens combination. The optical signal of the parallel light is detected by the detector. After detection, it is converted into a current signal, and the current signal is passed through an amplifying circuit to obtain an analog voltage, which is converted into a readable digital voltage value by a single-chip microcomputer, and the online detection value is obtained by using the quantitative model of the voltage value and the measured parameters.

Description

A photoelectric sensor measuring device

Technical field:

The invention belongs to the technical field of photoelectric sensing and measuring equipment, and relates to a photoelectric sensing and measuring device, which adopts the structure of a filter wheel and a wavelength-adjustable light source, and places bandpass filters of different wavelengths on the circumference of the rim of the filter wheel. In different transparent windows, the function of selecting the wavelength is realized by the rotation of the filter wheel.

Background technique:

With the advancement of the global industrialization process, the living standards of human beings are getting higher and higher, but the environmental problems are becoming more and more serious. Environmental pollution is seriously affecting the living environment of human beings, animals and plants. Water quality monitoring is the process of monitoring and measuring the types of pollutants in the water body, the concentration of various pollutants and the trend of change, and evaluating the water quality status. The scope of water quality monitoring is very wide, including unpolluted and polluted natural water (river, rivers, lakes, sea and groundwater) and various industrial drainage, etc. The main monitoring items of water quality can be divided into two categories: one is comprehensive indicators reflecting water quality, such as temperature, chromaticity, turbidity, pH value, conductivity, suspended solids, dissolved oxygen, chemical oxygen demand and biochemical demand. The other is some toxic substances, such as phenol, cyanide, arsenic, lead, chromium, cadmium, mercury and organic pesticides. In order to objectively evaluate the water quality of rivers and oceans, in addition to the above-mentioned monitoring items, it is sometimes necessary to measure the flow velocity and flow. At present, my country's water environment and water quality monitoring technology has achieved rapid development. Water quality monitoring technology is mainly based on physical and chemical monitoring technology, including chemical method, electrochemical method, atomic absorption spectrophotometry, ion selective electrode method, ion chromatography, Gas chromatography, plasma emission spectrometry (ICP-AES) method, etc. Among them, ion selective electrode method (qualitative, quantitative), chemical method (gravimetric method, volumetric titration method and spectrophotometric method) are widely used in routine monitoring of water quality at home and abroad. In recent years, biological monitoring and remote sensing monitoring technologies have also been applied to water quality monitoring.

Traditional physical and chemical monitoring: In the monitoring of surface water quality, due to the relatively simple monitoring instruments, physical monitoring index data are often relatively easy to obtain. Commonly used physical index monitoring instruments include turbidimeters for measuring water turbidity, and filter photometry for measuring chromaticity. Meter, conductivity meter for measuring conductivity, etc., and multi-functional water quality monitoring instrument to achieve the effect of simultaneous determination of multiple physical indicators. The monitoring of chemical indicators is the focus of surface water monitoring. With the country's emphasis on the monitoring of toxic organic pollution, certain progress has been made in the development and development of instruments. Some monitoring stations have introduced large and medium-sized laboratory monitors, which can be used on-site Monitor Zn, Fe, Pb, Cd, Hg, Mn and other heavy metals and halogen elements, ammonium nitrogen, nitrite nitrogen, cyanide, phenols, anionic detergents and Se and other substances.

Biological monitoring: Biological monitoring is one of the monitoring methods of water environment pollution. It uses the response of individual organisms, populations or communities to changes in environmental pollution to clarify the environmental pollution status. It is sensitive, enriched, long-term and comprehensive. Features. Currently, the biological monitoring methods that have been applied in actual monitoring mainly include biological index method, species diversity index method, microbiological community monitoring method, biological toxicity test, biological residue determination, ecophysiological and toxicological methods, etc. The aquatic organisms involved cover a single Cellular algae, protists, benthos, fish and amphibians.

Remote sensing monitoring technology: Remote sensing monitoring of inland water quality is based on experience, statistical analysis or spectral characteristics of water quality parameters, selecting remote sensing band data and ground measured water quality parameter data for mathematical analysis, and establishing a water quality parameter inversion algorithm. The water quality remote sensing monitoring method can reflect the distribution and changes of water quality in space and time, and find some pollution sources and pollutant migration characteristics that are difficult to reveal by conventional methods, and has the advantages of wide monitoring range, fast speed, low cost and convenient long-term dynamic monitoring .

Potassium permanganate titration is a redox titration method using potassium permanganate as a titrant. In a strongly acidic solution, potassium permanganate is a strong oxidant, and the acidity of the solution should be controlled at 1-2mol/L. If the acidity is too high, potassium permanganate is easy to decompose; if the acidity is too low, the reaction speed is slow, and manganese dioxide precipitation will occur. Sulfuric acid is commonly used to adjust the acidity of the solution. Because nitric acid is oxidizing, it should not be used. Hydrochloric acid is reducing and will be oxidized by potassium permanganate, so it is not suitable for use.

The principle of the potassium dichromate method is that in a strong acid solution, a certain amount of potassium dichromate oxidizes the reducing substances in the water sample, and the excess potassium dichromate uses ferrous iron as an indicator, and ferrous ammonium sulfate solution back drip. Calculate the oxygen consumed by the reducing substances in the water sample according to the amount. Acidic potassium dichromate has a strong oxidizing property and can oxidize most organic compounds. When silver sulfate is added as a catalyst, straight-chain aliphatic compounds can be completely oxidized, while aromatic organic compounds are not easily oxidized. Pyridine is not oxidized and is volatile. Chain aliphatic compounds, benzene and other organic substances exist in the vapor phase, and cannot be in contact with the oxidant liquid, and the oxidation is not obvious. Chloride ions can be oxidized by dichromate and react with silver sulfate to produce precipitation.

Among the above detection methods, potassium permanganate method and potassium dichromate method are commonly used water quality detection methods. Potassium permanganate method is suitable for measuring lightly polluted water samples, but is easily interfered by chloride ions; potassium dichromate The method is suitable for the determination of heavily polluted water samples, but it is greatly affected by the external environment; both methods have the disadvantages of long measurement time, complicated operation, and poor real-time performance. In recent years, since near-infrared and ultraviolet spectroscopy can analyze and detect material components in real time (the absorption of ultraviolet spectroscopy is more obvious), detection systems based on spectroscopy are increasingly being widely used. An online full-spectrum water quality analyzer disclosed in Chinese patent 201610872807.3 includes an optical path module and a measurement and control system, and the optical path module is connected to the measurement and control system through communication. Measuring channel unit, reference channel unit, first one-to-two optical fiber, collimation unit, focusing unit, second one-to-two fiber and spectrometer, the output end of the light source driving unit is connected to the driving end of the light source unit, so The light beam emitted by the light source unit is focused into the single end of the first one-divider optical fiber through the focusing collimation light-splitting unit, and the double ends of the first one-divider optical fiber enter the collimation unit respectively, and the light beam passes through the collimation unit Entering the beam selector, the light beam enters the measurement channel unit and the reference channel unit respectively through the beam selector, and the light beams output by the measurement channel unit and the reference channel unit enter the double ends of the second one-two optical fiber through the focusing unit respectively, so The single end of the second one-to-two optical fiber is connected to the input end of the spectrometer; Chinese patent 201611258828.2 discloses a multi-parameter water quality real-time online monitoring device based on spectroscopy, which includes a xenon lamp light source, a front optical path, a spectrum acquisition unit, and a fast Processing platform and output unit; the output light of the xenon light source passes through the front optical path and is divided into a calibration reference optical path and a measurement optical path; the calibration reference optical path enters the spectrum acquisition unit through the water sample to be tested; the measurement optical path enters the spectrum acquisition unit through the standard water sample ; Calibrate the reference light path and the measurement light path through the spectrum acquisition unit and convert them into two sets of spectral curve digital signals and then send them to the fast processing unit; the fast processing unit respectively processes the two sets of spectral curve digital signals to obtain the presence in the water sample to be tested. The substance to be tested and the concentration of the substance to be tested are output to the local or remote through the output unit to achieve monitoring; the fast processing unit is an ARM-based water quality multi-parameter intelligent processing platform; Chinese patent 201611217385.2 discloses a detection system based on ultraviolet-visible spectroscopy The water quality detection system includes a spectrum test unit one, a spectrum test unit two and a power supply, and the spectrum test unit one and the spectrum test unit two all include a light source, a detection probe and a spectrometer, and the spectrum test unit one and the spectrum test unit two respectively Connect with industrial computer 1 and industrial computer 2, industrial computer 1 and industrial computer 2 are connected with master control computer, described master control computer is respectively connected with alarm device, storage module, display module and instrument control module, instrument control module respectively A cleaning system and a flow path system are connected, the cleaning system is connected to the flow path system, and a sample pretreatment device is connected to the flow path system, and the flow path system provides test samples for the spectrum test unit 1 and the spectrum test unit 2 respectively, and the power supply Supply power to the system, the sample pretreatment device removes the impurities in the sample, and then collects the sample to the spectrum test unit 1 and spectrum test unit 2 through the flow system, the light source transmits the ultraviolet-visible light to the detection probe through the incident light path, and the light passes through the sample After absorption, it passes through the exit light path to the spectrometer, and the spectrometer converts the photoelectric signal into digital spectral data And transmit to industrial computer one and industrial computer two, industrial computer one and industrial computer two obtain the ultraviolet-visible light absorption spectrum of water quality respectively, and calculate water quality parameter, industrial computer one and industrial computer two transmit the water quality parameter calculated to The master control computer, the master control computer compares every two corresponding parameters, and when the difference exceeds the preset range, the alarm device is activated. If the difference does not exceed the preset range, the master control computer takes the average value of the two data As the final test data, the value is sent to the storage module and the display module for storage and display respectively. The cleaning system is controlled by the instrument control module to clean the flow system; Chinese patent 201720003938.8 discloses a multi-parameter water quality based on spectral analysis The detector includes a detection box, a collimated light source, an embedded system, and a single-chip control system. The detection box is equipped with a detection pool and an ultrasonic water tank. The detection pool and the ultrasonic water tank are separated by a partition. An electric heater, a collimated light source is installed on one side of the lower part of the detection box, a focuser is installed on the other side of the lower part of the detection box, a spectrum analyzer is installed on the side of the focuser, and the signal output terminal of the spectrum analyzer is connected to the embedded system. The embedded system and the single-chip control system are connected through serial communication, and an ultrasonic generator is installed at the bottom of the detection box, and the ultrasonic generator is connected with the ultrasonic transducer; a multi-parameter water quality based on spectroscopy disclosed in Chinese patent 201621477557.5 The real-time online monitoring device includes a xenon lamp light source, a front optical path, a spectrum acquisition unit, a fast processing platform, and an output unit; the output light of the xenon light source passes through the front optical path and is divided into a calibration reference optical path and a measurement optical path; the calibration reference optical path passes through the water to be measured The sample is incident to the spectrum acquisition unit; the measurement light path is incident to the spectrum acquisition unit through the standard water sample; the calibration reference light path and the measurement light path are synchronously acquired by the spectrum acquisition unit and then converted into two sets of spectral curve digital signals and sent to the fast processing unit; the fast processing unit After processing the digital signals of the two sets of spectral curves respectively, the substances to be tested and the concentration of the substances to be tested are obtained in the water samples to be tested, and then output to the local or remote through the output unit to realize monitoring; the fast processing unit is an ARM-based water quality multiplexer Parameter intelligent processing platform; Chinese patent 201710909925.1 discloses a rotary adjustable spectrum analyzer including a fixed base plate and a weldment, the fixed base plate is equipped with a support plate, the threaded seat is provided with a stud, and the stud A sleeve is installed at one end, a fixed rod is installed at one end of the sleeve, a fastening seat is installed at one end of the fixed rod, a locking bolt is arranged on the surface of the fastening seat, and a U Type fixing frame, one end of the U-shaped fixing frame is equipped with a strong suction cup, and there are four strong suction cups in total, two strong suction cups form a group, and a spectrum analyzer is arranged between the two groups of strong suction cups, and the support The top of the board is equipped with a foot seat, and a dust cover is installed on the foot seat; the spectral analysis technology can not only analyze the composition of the substance, but also use the absorbance of the spectrum to correlate with the concentration of the substance. It is easy to operate, fast in analysis speed, and has no secondary pollution. The spectroscopic method of measuring water quality is more in line with the development concept of modern measuring instruments; but the above patented products and spectral analysis equipment in the prior art are expensive , the volume is large, which is not conducive to real-time on-site detection. Therefore, the development and design of a small, portable, low-cost, convenient and practical photoelectric sensing and measuring device has good social and economic value and broad application prospects.

Invention content:

The purpose of the present invention is to overcome the shortcomings of the prior art, to develop and design a small and light, low-cost, easy-to-use and practical photoelectric sensing measuring device, which adopts the structure of filter wheel and wavelength-tunable light source to convert different The band-pass filter of the wavelength is placed in different transparent windows around the rim of the filter wheel, and the function of selecting the wavelength is realized by the rotation of the filter wheel for rapid analysis and water quality monitoring without secondary pollution.

In order to achieve the above object, the main structure of the photoelectric sensing measuring device involved in the present invention includes a base, No. 1 bracket, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket, No. 6 bracket, light source, polarizer, Lens combination, motor, filter wheel, through hole, filter, transparent window, sample compartment, front conduit, rear conduit and detector; the upper surface of the base of the rectangular plate structure is provided with No. 1 support, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket and No. 6 bracket, the base is connected with No. 1 bracket, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket and No. 6 bracket respectively, A light source is installed on the top of the No. 1 bracket, a polarizer is installed on the top of the No. 2 bracket, and a lens combination is installed on the top of the No. 3 bracket. The main structure of the lens combination includes a large-diameter collimator lens, a focusing lens and a small-diameter collimator lens. , the large-diameter collimator lens, focus lens and small-diameter collimator lens are arranged in sequence from left to right, the centers of the large-diameter collimator lens, focus lens and small-diameter collimator lens are located on the same straight line, and the top of the No. 4 bracket is installed There is a motor, and the motor is connected with the filter wheel of circular structure, and there are n-2 through holes of circular structure equally spaced on the circumference of the filter wheel, among which n-1 through holes are equipped with circular sheet structures Filters with different wavelengths, a transparent window with a circular structure is installed in the other one through hole, a sample chamber with an inner hollow cuboid structure is installed on the top of the No. 5 bracket, and a circular The front guide tube of the structure, the rear guide tube of the circular structure is arranged on the rear side of the sample chamber, and the detector is arranged on the top of the No. on the horizontal light path.

The materials of the base, No. 1 bracket, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket and No. 6 bracket involved in the present invention are all stainless steel; , superradiant light source, semiconductor optical amplifier, fiber amplifier, non-single-mode light from space and wide-spectrum light source from compound light source; polarizer can obtain polarized light from natural light; the large-diameter collimator lens in the lens combination is light-passing The collimating lens with an aperture of 1 mm to 7 cm, the focusing lens is a transmission lens, and the small-diameter collimating lens is a collimating lens with a clear aperture of 0.01 mm to 1 cm; the motor is a geared motor, a servo motor or a DC stepper The motor, when the motor rotates, drives the filter wheel to rotate to select the optical path lens combination-the filter of different wavelengths in the sample chamber; the number of through holes on the filter wheel is selected according to the number of filters of different wavelengths required. The number of holes is 1 more than the number of filters; the filter is a band-pass filter; the transparent window is used as the passage window for the test light source emitting other wavelengths; the sample chamber is used to store the liquid to be tested; The liquid to be measured flows into the channel of the sample chamber; the rear conduit is used as the channel for the liquid to be measured to flow out of the sample chamber; the detector is a photon detector.

When the photoelectric sensor measuring device involved in the present invention is used, the through holes on the filter wheel are numbered as 0, 1, 2, 3...N in sequence, and in the through holes numbered 1, 2, 3...N Insert filters of different wavelengths in sequence, and the corresponding wavelengths of the filters are λ ₁ , λ ₂ ... λ _N , and the through hole numbered 0 without a filter is a transparent window, on the left side of the transparent window The test light source is installed on the side, and the photodetector is installed on the right side of the transparent window. The wavelength of the test light source is λ ₀ , and the light paths of the test light source and the photodetector are on the same axis. Natural light, the wavelength _λ0 is a wavelength included in the spectral band of the test light source, and the photodetector can detect the light with a wavelength of _λ0 ; the motor is turned on to drive the filter wheel to rotate, and the lens combination and the filter in the No. 1 through hole When the centers of the light sheet, the sample chamber and the detector are on the same horizontal optical path, turn on the light source, the light source emits natural light, the polarizer obtains the polarized light in the natural light, and when the polarized light passes through the large-diameter collimator lens, it is captured by the large-diameter collimator lens Coupling into parallel light, when the parallel light passes through the focusing lens, it is focused by the focusing lens into light with a small light field range, and when the light with a small light field range passes through a small-diameter collimator lens, it is coupled into a parallel light with a small light field range by the small-diameter collimator lens Light, the parallel light in the small light field range passes through the filter in the No. 1 through hole and becomes monochromatic light. After the monochromatic light passes through the sample chamber, an optical signal carrying sample information is formed. The detector converts the detected optical signal into The current signal, the current signal is passed through the amplifying circuit to obtain the analog voltage, and the analog voltage is converted into a readable digital voltage value through the single-chip analog-to-digital conversion, and the online detection value can be obtained by using the digital voltage value and the quantitative model of the measured parameters; during the period, when the photodetector When the optical signal sent by the test light source is detected, it means that the optical filter in the No. 1 through hole is on the optical axis of the optical path lens combination-sample chamber, and what the detector detects is an optical signal with a wavelength of _λ1 , and the filter wheel is at a constant speed The time to rotate one circle is T, the filter wheel has N through holes, and the detector detects an optical signal P every T/N time, P is the optical signal corresponding to the wavelength λ, and the optical signal detected by the photodetector is P ₀ , and P ₀ is the optical signal corresponding to wavelength λ ₀ , then the corresponding relationship between wavelength λ, optical signal P and P ₀ and time T is shown in the following table:

It can be seen from the above table that the test light source and photodetector can accurately locate the wavelength λ, and can also accurately locate other wavelengths, so as to accurately obtain the response of the detector to different wavelengths.

Compared with the prior art, the present invention designs a transparent window on the circumference of the filter wheel, and installs a test light source and a photodetector on the coaxial optical path corresponding to the transparent window to accurately locate the wavelength and filter the light. The combination of wheel and light source, polarizer, lens combination, sample chamber, detector and simple mechanical support is made into a photoelectric sensing and measuring device based on a wavelength-tunable light source. The motor drives the filter wheel to rotate, thereby changing the optical path. Lens combination-sample The filter working in the warehouse is used to accurately locate different wavelengths. The polarizer captures the polarized light in the natural light emitted by the light source and combines it with lenses to form parallel light. The optical signal of the parallel light is detected by the detector and converted into a current signal. The current signal is passed through the amplifying circuit to obtain the analog voltage, and then converted into a readable digital voltage value through the single-chip analog-to-digital conversion, and the online detection value can be obtained by using the quantitative model of the voltage value and the measured parameters; its structure is simple, small and light, low cost, and easy to use It is easy to make, fast to use, strong in real-time, and there is no secondary pollution, especially suitable for deep ultraviolet light bands.

Description of drawings:

Fig. 1 is a schematic diagram of the principle of the main structure of the present invention.

FIG. 2 is a schematic diagram of the main structure of the lens combination involved in the present invention.

FIG. 3 is a schematic diagram of the main structure of the filter wheel involved in the present invention.

Fig. 4 is a schematic diagram of the main structure of the sample chamber involved in the present invention.

Fig. 5 is a schematic diagram of the principle of wavelength positioning performed by the photoelectric sensing and measuring device involved in the present invention.

Detailed ways:

The present invention will be further described below through the embodiments and in conjunction with the accompanying drawings.

Example 1:

The main structure of the photoelectric sensing and measuring device involved in this embodiment includes a base 1, a No. 1 bracket 2, a No. 2 bracket 3, a No. 3 bracket 4, a No. 4 bracket 5, a No. 5 bracket 6, a No. 6 bracket 7, a light source 8, Polarizer 9, lens combination 10, motor 11, filter wheel 12, through hole 13, optical filter 14, transparent window 15, sample chamber 16, front conduit 17, rear conduit 18 and detector 19; rectangular plate-shaped structure The upper surface of the base 1 is provided with No. 1 bracket 2, No. 2 bracket 3, No. 3 bracket 4, No. 4 bracket 5, No. 5 bracket 6 and No. 6 bracket 7 from left to right. , No. 2 bracket 3, No. 3 bracket 4, No. 4 bracket 5, No. 5 bracket 6 and No. 6 bracket 7 are connected by bolts, the top of No. 1 bracket 2 is equipped with a light source 8, and the top of No. 9, the top of No. 3 bracket 4 is equipped with a lens assembly 10, the main structure of the lens assembly 10 includes a large-diameter collimator lens 101, a focusing lens 102 and a small-diameter collimating lens 103, a large-diameter collimating lens 101, a focusing lens 102 and the small-diameter collimator lens 103 are arranged sequentially from left to right, the centers of the large-diameter collimator lens 101, the focusing lens 102 and the small-diameter collimator lens 103 are located on the same straight line, and the top of the fourth bracket 5 is equipped with a motor 11, The motor 11 is connected with the filter wheel 12 of circular structure, and the circumference of the filter wheel 12 is equidistantly provided with n-2 (n is an integer greater than 2) circular structure through-holes 13, wherein n-1 through-holes 13 The hole 13 is equipped with a circular plate-shaped optical filter 14 with different wavelengths, and the other through hole 13 is equipped with a circular transparent window 15, and the top of the fifth bracket 6 is equipped with an inner hollow cuboid structure. Sample chamber 16, a front conduit 17 of circular structure is arranged on the front side of the sample chamber 16, a rear conduit 18 of circular structure is arranged on the rear side of the sample chamber 16, and a detector is arranged on the top of No. 6 bracket 7 19; the centers of the lens assembly 10, one of the optical filters 14, the sample chamber 16 and the detector 19 are on the same horizontal optical path.

Base 1, No. 1 bracket 2, No. 2 bracket 3, No. 3 bracket 4, No. 4 bracket 5, No. 5 bracket 6 and No. 6 bracket 7 involved in this embodiment are all made of stainless steel; the light source 8 is composed of a deuterium lamp, Tungsten-halogen lamps, xenon lamps, light-emitting diodes (LEDs), superradiant light sources, semiconductor optical amplifiers, fiber amplifiers, non-single-mode light (sunlight) from space, and composite light sources (luminous wavelengths from ultraviolet, visible to infrared) have a wide range of Spectrum light source; polarizer 9 can obtain polarized light from natural light; large-diameter collimator lens 101 in lens combination 10 is a collimator lens with a light-passing diameter of 1 millimeter to 7 centimeters, and focusing lens 102 is a transmissive lens, small Aperture collimating lens 103 is a collimating lens with a clear aperture of 0.01 mm to 1 cm; motor 11 is a geared motor, a servo motor or a DC stepping motor, and when the motor 11 rotates, it drives the filter wheel 12 to rotate to select the optical path lens combination 10 -the optical filter 14 of different wavelengths in the sample chamber 16; The number is one more; the filter 14 is a band-pass filter; the transparent window 15 is used as the passage window for the test light source 200 emitting other waveband wavelengths; the sample chamber 16 is used to store the liquid to be tested; the front conduit 17 is used as the liquid to be tested The channel that flows into the sample chamber 16; the rear conduit 18 serves as a channel for the liquid to be tested to flow out of the sample chamber 16; the detector 19 is a photon detector.

When the photoelectric sensing and measuring device involved in the present embodiment is in use, the through holes 13 on the filter wheel 12 are numbered as 0, 1, 2, 3...N in turn, and in the numbered 1, 2, 3...N Filters 14 of different wavelengths are sequentially placed in the through holes 13, and the wavelengths corresponding to the filters 14 are respectively λ ₁ , λ ₂ ... λ _N , and the through holes 13 numbered 0 without the filters 14 are Transparent window 15, test light source 200 is installed on the left side of transparent window 15, photodetector 300 is installed on the right side of transparent window 15, the wavelength of test light source 200 is λ ₀ , the optical path of test light source 200 and photodetector 300 Located on the same axis, the test light source 200 includes lasers, light-emitting diodes, lamps and natural light, and the wavelength λ ₀ is a wavelength included in the test light source 200 spectral bands, and the photodetector 300 can detect the light of the wavelength λ ₀ ; turn on the motor 11 to make it drive the filter wheel 12 to rotate, and when the centers of the lens combination 10, the filter 14 in the No. 1 through hole 13, the sample chamber 16 and the detector 19 are on the same horizontal optical path, turn on the light source 8 and the light source 8 Natural light is emitted, and the polarizer 9 acquires polarized light in the natural light. When the polarized light passes through the large-diameter collimator lens 101, it is coupled into parallel light by the large-diameter collimator lens 101. When the parallel light passes through the focusing lens 102, it is focused by the focusing lens 102 into a small The light in the light field range, when the light in the small light field range passes through the small-diameter collimator lens 103, it is coupled by the small-diameter collimator lens 103 into parallel light in the small light field range, and the parallel light in the small light field range passes through the No. 1 through hole 13 After the filter 14 in the filter becomes monochromatic light, the monochromatic light forms an optical signal carrying sample information after passing through the sample chamber 16, and the detector 19 converts the detected optical signal into a current signal, and the current signal passes through an amplifying circuit to obtain an analog voltage , the analog voltage is converted into a readable digital voltage value through the single-chip analog-to-digital conversion, and the online detection value can be obtained by using the digital voltage value and the quantitative model of the measured parameters; , illustrate that the optical filter 14 in the No. 1 through hole 13 is on the optical axis of the optical path lens combination 10-sample chamber 16, and what the detector 19 detects is an optical signal with a wavelength of λ ₁ , and the optical filter wheel 12 rotates at a constant speed. The time is T, the filter wheel 12 has N through holes 13, the detector 19 detects an optical signal P every T/N time, P is the optical signal corresponding to the wavelength λ, and the light detected by the photodetector 300 The signal is P ₀ , and P ₀ is the optical signal corresponding to wavelength λ ₀ , then the corresponding relationship between wavelength λ, optical signal P and P ₀ and time T is shown in the following table:

T 0 T/N 2T/N ... (N-1)T/N T T+T/N T+2T/N ... lambda λ1 λ2 λ3 ... λN λ1 λ2 λ3 ... P ₀ 1 0 0 ... 0 1 0 0 ... P _{P1 P2} P ₃ ... P _{n P1 P2} P ₃ ...

It can be seen from the above table that the test light source 200 and the photodetector 300 can accurately locate the wavelength λ, and can also accurately locate other wavelengths, so as to accurately obtain the response of the detector 19 to different wavelengths.

Claims (3)

1. A photoelectric sensing measuring device, characterized in that the main structure includes a base, No. 1 bracket, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket, No. 6 bracket, light source, polarizer, lens combination , motor, filter wheel, through hole, filter, transparent window, sample chamber, front conduit, rear conduit and detector; the upper surface of the base of the rectangular plate structure is provided with No. 1 bracket and No. 2 bracket from left to right. Bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket and No. 6 bracket, the base is connected with No. 1 bracket, No. 2 bracket, No. 3 bracket, No. 4 bracket, No. 5 bracket and No. A light source is installed on the top of the bracket, a polarizer is installed on the top of the No. 2 bracket, and a lens combination is installed on the top of the No. 3 bracket. The collimator lens, focusing lens and collimating lens with small diameter are arranged in order from left to right. The centers of the collimating lens with large diameter, the focusing lens and the collimating lens with small diameter are located on the same straight line. The motor is installed on the top of the fourth bracket. , the motor is connected to the filter wheel with a circular structure, and there are n-2 through holes with a circular structure at equal intervals on the circumference of the filter wheel, wherein n-1 through holes are equipped with wavelengths of a circular sheet structure For different optical filters, a transparent window with a circular structure is installed in the remaining one through hole, a sample chamber with an inner hollow cuboid structure is installed on the top of the No. 5 bracket, and a circular structure is installed on the front side of the sample chamber. The front conduit, the back conduit of the circular structure is arranged on the rear side of the sample chamber, and the detector is arranged on the top of the No. on the way. 2. A kind of photoelectric sensing measuring device according to claim 1, characterized in that the materials of the base, No. 1 support, No. 2 support, No. 3 support, No. 4 support, No. 5 support and No. 6 support are all It is stainless steel; the light source is a wide-spectrum light source including a deuterium lamp, a tungsten halogen lamp, a xenon lamp, a light-emitting diode, a superradiant light source, a semiconductor optical amplifier, an optical fiber amplifier, non-single-mode light from space, and a composite light source; the polarizer can be used from Obtain polarized light in natural light; the large-diameter collimator lens in the lens combination is a collimator lens with a clear diameter of 1 mm to 7 cm, the focusing lens is a transmission lens, and the small-diameter collimator lens is a clear diameter of 0.01 mm to 1 cm collimating lens; the motor is a geared motor, servo motor or DC stepping motor, and when the motor rotates, it drives the filter wheel to rotate to select the optical path lens combination-filters of different wavelengths in the sample compartment; the filter wheel on the filter wheel The number of through holes is selected according to the number of filters of different wavelengths required. The number of through holes is one more than the number of filters; The test light source passes through the window; the sample chamber is used to store the liquid to be tested; the front conduit is used as a channel for the liquid to be tested to flow into the sample chamber; the rear conduit is used as a channel for the liquid to be tested to flow out of the sample chamber; the detector is a photon detector. 3. The photoelectric sensing and measuring device according to claim 1, wherein when in use, the through holes on the filter wheel are numbered 0, 1, 2, 3...N in sequence, and numbered 1, 2 , 3...N through-holes are sequentially placed with filters of different wavelengths, the corresponding wavelengths of the filters are λ ₁ , λ ₂ ... λ _N , and the through-holes numbered 0 without filters As a transparent window, a test light source is installed on the left side of the transparent window, and a photodetector is installed on the right side of the transparent window. The wavelength of the test light source is λ ₀ . The light source includes a laser, a light-emitting diode, a lamp and natural light, and the wavelength _λ0 is a wavelength included in the spectral band of the test light source, and the photodetector can detect the light with a wavelength of _λ0 ; the motor is turned on to drive the filter wheel to rotate, and the lens When the center of the combination, the optical filter in the No. 1 through hole, the sample chamber and the detector are on the same horizontal optical path, turn on the light source, the light source emits natural light, the polarizer obtains the polarized light in the natural light, and the polarized light passes through a large-aperture collimator When a straight lens is used, it is coupled into parallel light by a large-diameter collimator lens. When the parallel light passes through the focusing lens, it is focused by the focusing lens into light in a small light field range. When the light in a small light field range passes through a small-diameter collimator lens, it is collimated by a small diameter. The lens is coupled to parallel light with a small light field range. The parallel light with a small light field range passes through the filter in the No. 1 through hole and becomes monochromatic light. The monochromatic light forms an optical signal carrying sample information after passing through the sample chamber. The detector converts the detected optical signal into a current signal, and the current signal is passed through an amplifying circuit to obtain an analog voltage, and the analog voltage is converted into a readable digital voltage value through a single-chip microcomputer analog-to-digital conversion, and the quantitative model of the digital voltage value and the measured parameters can be obtained online. Detection value; during the period, when the photodetector detects the light signal sent by the test light source, it means that the filter in the No. 1 through hole is on the optical axis of the optical path lens combination-sample chamber, and what the detector detects is the wavelength λ ₁ optical signal, the time for the filter wheel to rotate at a constant speed is T, the filter wheel has N through holes, and the detector detects an optical signal P every T/N time, P is the optical signal corresponding to the wavelength λ , the optical signal detected by the photodetector is P ₀ , and P ₀ is the optical signal corresponding to wavelength λ ₀ , then the corresponding relationship between wavelength λ, optical signals P and P ₀ and time T is shown in the following table: T 0 T/N 2T/N ... (N-1)T/N T T+T/N T+2T/N ... lambda λ1 λ2 λ3 ... λN λ1 λ2 λ3 ... P ₀ 1 0 0 ... 0 1 0 0 ... P _{P1 P2} P ₃ ... P _{n P1 P2} P ₃ ... It can be seen from the above table that the test light source and photodetector can accurately locate the wavelength λ, and can also accurately locate other wavelengths, so as to accurately obtain the response of the detector to different wavelengths.