Optical assembly for directly measuring original valence state, original form, and original phase state of high-concentration liquid in real time

Abstract

An optical assembly for directly measuring an original valence state, an original form, and an original phase state of a high-concentration liquid in real time, comprising a PLC control module, a monochromatic light purification module, a light intensity control module, a sensitivity adjustment module, and a multi-species sensing module. On the basis of different species monitoring requirements, under the control of the PLC control module, the monochromatic light purification module emits monochromatic light, the light intensity control module adjusts the light intensity of the monochromatic light, the sensitivity adjustment module adjusts the attenuation of the monochromatic light, and the multi-species sensing module feeds back a measurement signal of the monochromatic light to the PLC control module. According to the principles that the center spectral line bandwidth is the narrowest, absorbed light intensity is the highest, and transmitted light sensitivity is the highest, closed-loop feedback of the PLC control module and the multi-species sensing module is used to intelligently search for high-purity incident light wavelengths required for accurately matching different species, and the optimal incident light energy and multi-optical path combination matching different concentrations of species are automatically adjusted, so as to achieve second-level synchronous direct measurement of valence state, form, and phase state concentrations of a high-concentration liquid containing different species.

Description

Real-time direct measurement of high-concentration liquid original valence state original form original phase optical assembly TECHNICAL FIELD

[0001] The present application relates to the field of detection and analysis of high-concentration complex liquid multi-species original valence state original form original phase in process industry, in particular to a real-time direct measurement of high-concentration liquid original valence state original form original phase optical assembly. BACKGROUND

[0002] The multi-element chemical reaction process of process industry generally exists the phenomenon of fast reaction speed, multiple reaction species, gas-solid-liquid coexistence, and coexistence of different species in solution with multiple valence states, multiple forms and multiple phases, and large concentration span (some phases differ by up to tens of thousands of times). Among them, not only the concentration of the species, but especially the valence state, form and phase of the species determine the product quality, production cost, pollutant quantity and toxicity in the liquid phase system of industrial production process. This is because the valence state, form and phase of the microcosmic chemical process species are closely related to chemical reaction thermodynamics and kinetics, and directly affect whether a unit reaction can occur or the extent of the reaction. Therefore, measuring the valence state, form and phase of the species is very important for improving product quality, reducing production cost, pollutant quantity and toxicity in industrial production process.

[0003] At present, domestic and foreign analysis methods can only determine the total amount or single valence state of elements in the solution, and cannot analyze the real valence state and form of the species. The methods widely used by enterprises, such as inductively coupled plasma emission spectrometry / mass spectrometry, atomic fluorescence spectrometry, national standard spectrophotometry, etc., whether offline or online, can monitor low-concentration pollutants in the external environment, but in the monitoring of high-concentration liquid phase systems in industrial processes, all of them need to pretreat the sample, change the valence state, form and phase of the chemical species, cause the dosage of reagents to deviate or even wrong reagents to be added, take a long time, and have obvious secondary pollution risk, the upper limit of detection is only in the milligram level, the detection result is seriously lagged in time, it is difficult to realize real-time feedback control of industrial process, and it cannot meet the needs of enterprise production, safety and environmental protection.

[0004] SUMMARY

[0005] In view of the above problems existing in the prior art, the application provides a kind of optical assembly for real-time direct measurement of high-concentration liquid original valence state original form original phase state, comprising PLC control module, monochromatic light purification module, light intensity adjusting module, sensitivity adjusting module and multi-species sensing module, for the demand of different species characteristic spectrum corresponding to different wavelength high-purity light, different concentration absorption spectrum corresponding to different incident light, utilize the transmission light intensity signal of multi-wavelength receiving module under different optical path combination conditions, first according to the principle of maximum absorption light intensity, the narrowest central spectral line bandwidth, intelligently search for the high-purity incident light wavelength required for accurate matching of different species, then according to the principle of high absorption, high transmission, high sensitivity, automatically adjust the best incident light energy matched with different concentration species, through coupling high-purity light extraction, light energy regulation, multi-optical path combination and multi-wavelength receiving optical assembly, realize the second-level synchronous direct measurement of different species valence state form phase state concentration.

[0006] The technical scheme of the application is as follows:

[0007] An optical assembly for real-time direct measurement of high-concentration liquid original valence state original form original phase state, comprising a PLC control module, a monochromatic light purification module, a light intensity control module, a sensitivity adjusting module and a multi-species sensing module.

[0008] The monochromatic light purification module comprises a power switch, a power adapter, a multi-wavelength multi-light intensity light source and a multi-wavelength multi-stage filter disc; the power switch and the power adapter convert 220V alternating current into 5V / 2A direct current to power the multi-wavelength multi-light intensity light source; the multi-wavelength multi-light intensity light source emits composite light.

[0009] The multi-wavelength multi-stage filter disc comprises a filter disc 1, a filter disc 2 and a servo motor 3; the filter disc 1 is provided with a circular hole, and the number of the circular holes is not less than 2; the filter disc 2 is installed on the circular holes, and the center wavelengths and spectral line bandwidths of the filter discs 2 in different circular holes are different; the filter disc 1 has a total of 2, and the circular holes of the two filter discs 1 are one-to-one corresponding and coinciding, and the center wavelengths and spectral line bandwidths of the filter discs 2 installed on the two coinciding circular holes are different.

[0010] The composite light emitted by the multi-wavelength multi-light intensity light source successively transmits through the two filter discs 2 on the circular holes of the multi-wavelength multi-stage filter disc, becoming monochromatic light.

[0011] The two filter discs 1 are fixedly connected with the servo motor 3 to form an integral whole; under the drive of the servo motor 3, the two filter discs 1 make circular motion around their own central axes, so that different circular holes and filter discs 2 move in front of the composite light, and different center wavelength monochromatic light is obtained by filtering;

[0012] The incident light intensity of the monochromatic light is defined as I0, and the absorption light intensity absorbed by the target species is defined as I aThe transmission intensity from the target species to the multi-species perception module is defined as I t , that is, I0=I a +I t ;

[0013] The light intensity control module includes a power / current stepless regulator; the PLC control module changes I0of the monochromatic light by adjusting the knob of the power / current stepless regulator, and satisfies the following conditions:

[0014] When the concentration of the target species changes between the minimum value and the maximum value, the multi-species perception module can still receive the signal of the monochromatic light after the monochromatic light is attenuated by the target species, that is, I t > 0;

[0015] The sensitivity adjustment module is composed of flow cells with different optical paths, and different optical paths are adjusted according to different concentrations of the target species; when the concentration of the target species is relatively large, the optical path is adjusted to be small, so that the total amount of the target species transmitted by the monochromatic light is relatively small; when the concentration of the target species is relatively small, the optical path is adjusted to be large, so that the total amount of the target species transmitted by the monochromatic light is relatively large; finally, the monochromatic light received by the multi-species perception module satisfies the following conditions:

[0016] (1) Under different concentration conditions, the light absorption sensitivity ΔIa of the target species is maximum;

[0017] (2) When the target species is at the maximum concentration, the multi-species perception module receives the signal of the monochromatic light, that is, I t > 0;

[0018] (3) When the target species is at the minimum concentration, the multi-species perception module receives the attenuated monochromatic light, that is, I0>I t > 0;

[0019] The multi-species perception module includes a photoelectric receiver and a signal amplifier, receives the monochromatic light of different central wavelengths corresponding to different target species, the transmission light intensity I t under different incident light intensities and different optical path conditions corresponding to different concentrations, and converts the received light signal into an electrical signal and amplifies it, and then feeds back to the PLC control module in real time.

[0020] Further, the wavelength range of the composite light is 180-900nm;

[0021] The spectral line bandwidth of the filter 2 is ±0.03nm;

[0022] The optical path range of the sensitivity adjustment module is 0.5mm-100mm.

[0023] Further, the working process is as follows:

[0024] S1, the PLC control module sends an instruction 1 to the monochromatic light purification module to measure the target species according to the target species valence state morphology phase concentration requirement of the upper computer;

[0025] S2, the monochromatic light purification module starts the multi-wavelength multi-light intensity light source according to the instruction 1, rotates the multi-wavelength multi-stage filter disc, and outputs high-purity monochromatic light; the high-purity monochromatic light output at this time is called output 1; at this time, the light intensity adjusting module and the sensitivity adjusting module are not put into work, and the output 1 directly reaches the multi-species perception module;

[0026] S3, the multi-species perception module measures the output 1 to obtain a measurement result, i.e. feedback 1, and sends the feedback 1 to the PLC control module;

[0027] S4, the PLC control module selects a filter 2 of the multi-wavelength multi-stage filter disc according to the feedback 1 until the monochromatic light with the best center wavelength and spectral line bandwidth that meets the requirements of the instruction 1 is obtained; the monochromatic light at this time is called the best incident light;

[0028] S5, the PLC control module sends an instruction 2 containing the minimum and maximum concentration change range of the target species to the light intensity control module;

[0029] S6, the light intensity control module dynamically adjusts the knob of the power / current stepless regulator from small to large according to the instruction 2, so that the monochromatic light purification module emits monochromatic light with different light intensities I0; the monochromatic light output at this time is called output 2; at this time, the sensitivity adjusting module is not put into work, and the output 2 directly reaches the multi-species perception module;

[0030] S7, the multi-species perception module measures the output 2 to obtain a measurement result, i.e. feedback 2, and sends the feedback 2 to the PLC control module;

[0031] S8, the PLC control module adjusts the knob of the power / current stepless regulator according to the feedback 2 to form a closed-loop control until the light intensity I0 of the best incident light that meets the following conditions is obtained:

[0032] When the concentration of the target species changes between the minimum concentration and the maximum concentration, the multi-species perception module can receive the transmission signal of the best incident light, i.e. I t > 0;

[0033] S9, the PLC control module sends an instruction 3 containing the high-frequency concentration change range of the target species to the sensitivity adjusting module;

[0034] S10, the sensitivity adjusting module automatically adjusts the combination of the flow cell from small to large according to the instruction 3, so that the light path of the monochromatic light passing through the sensitivity adjusting module changes; the monochromatic light emitted by the sensitivity adjusting module is called output 3;

[0035] S11, the multi-species sensing module measures output 3 to obtain a measurement result, i.e., feedback 3, and sends the feedback 3 to the PLC control module;

[0036] S12, the PLC control module adjusts the optical path of the sensitivity adjustment module according to the feedback 3 to form a closed-loop control until an optimal optical path that satisfies the following conditions is obtained:

[0037] (1) under different concentration conditions, the light absorption sensitivity of the target species ΔIa is maximum;

[0038] (2) when the target species is at the maximum concentration, the monochromatic light received by the multi-species sensing module has a signal, i.e., I t > 0;

[0039] (3) when the target species is at the minimum concentration, the monochromatic light received by the multi-species sensing module has an attenuation, i.e., I0> I t > 0.

[0040] The beneficial technical effects of the present application are:

[0041] According to the principle of the narrowest central spectral line bandwidth, the highest absorption light intensity, and the maximum transmission light sensitivity, the closed-loop feedback of the PLC control module and the multi-species sensing module is used to intelligently search for a high-purity incident light wavelength that accurately matches different species, and to automatically adjust the optimal incident light energy and multi-optical path combination matched with different concentrations of species, thereby realizing the second-level synchronous direct measurement of the valence state, morphology, and concentration of different species. BRIEF DESCRIPTION OF DRAWINGS

[0042] Fig. 1 is a system principle diagram of the embodiment;

[0043] Fig. 2 is a structural diagram of a multi-wavelength multi-stage filter disc.

[0044] In the figure, the correspondence between the component names and the figure numbers is as follows: 1, filter disc; 2, filter; 3, servo motor. DETAILED DESCRIPTION

[0045] The present application will be described in detail below in conjunction with the drawings and embodiments. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative labor fall within the scope of protection of the present application.

[0046] As shown in Fig. 1, the embodiment includes a PLC control module, a monochromatic light purification module, a light intensity control module, a sensitivity adjustment module, and a multi-species sensing module.

[0047] The hardware of the PLC control module is a Siemens PLC S7-1200, which can issue instructions to the monochromatic light purification module, the light intensity control module, the sensitivity adjustment module and the multi-species perception module according to the target species valence state morphology phase concentration requirements, and receive the feedback signals of the multi-species perception module.

[0048] The monochromatic light purification module includes a power switch, a power adapter, a multi-wavelength multi-intensity light source and a multi-wavelength multi-stage filter disc. The power switch and the power adapter convert 220V alternating current into 5V / 2A direct current to power the multi-wavelength multi-intensity light source; the multi-wavelength multi-intensity light source can emit composite light with a wavelength range of 180-900nm; the multi-wavelength multi-stage filter disc can provide a variety of center wavelength filters with a spectral line bandwidth of ±0.03nm, which can purify the composite light emitted by the multi-wavelength multi-intensity light source into high-purity monochromatic light (hereinafter referred to as monochromatic light), meeting the requirements of the target species.

[0049] The structure of the multi-wavelength multi-stage filter disc is shown in Figure 2, which includes a filter disc 1, a filter 2 and a servo motor 3. The filter disc 1 is provided with six circular holes, and the filter 2 is installed on the circular holes. The center wavelength and spectral line bandwidth of the filter 2 in different circular holes are different. The filter disc 1 has a total of two, and the circular holes of the two filter discs 1 are one-to-one corresponding and coinciding, and the center wavelength and spectral line bandwidth of the filters 2 installed on the two coinciding circular holes are different. The purpose of this design is to realize double-layer filtering, so as to obtain monochromatic light with higher purity.

[0050] The composite light emitted by the multi-wavelength multi-intensity light source successively passes through the two filters 2 on the circular holes of the multi-wavelength multi-stage filter disc, becoming monochromatic light.

[0051] The two filter discs 1 are fixedly connected with the servo motor 3 as a whole. Under the drive of the servo motor 3, the two filter discs 1 make circular motion around their own center axis, so that different circular holes and filters 2 move in front of the composite light, thereby filtering monochromatic light with different center wavelengths and spectral line bandwidths.

[0052] The incident light intensity of the monochromatic light is I0, and the absorption light intensity absorbed by the target species is I a The transmission intensity transmitted from the target species to the multi-species perception module is I t , that is, I0=I a +I t . In order to ensure that the multi-species perception module can still receive the signal of the monochromatic light after the monochromatic light is absorbed and attenuated by the sample, it is necessary to ensure that the incident light intensity I0 meets the following conditions:

[0053] I0-I a =I t >0, that is: I0>I a

[0054] The light intensity adjusting module includes a power / current stepless regulator, which can dynamically adjust the light intensity of the monochromatic light to meet the requirements of the target species for light intensity I a and transmission intensity I t . The PLC control module adjusts the knob of the power / current stepless regulator, so that the current of the multi-wavelength multi-intensity light source changes from small to large, and when the concentration of the target species changes between the minimum and maximum values, the adapted incident light intensity I0 can be provided to ensure that the multi-species perception module can still receive the signal of the monochromatic light after the monochromatic light is absorbed and attenuated by the target species.

[0055] The sensitivity adjusting module is composed of flow cells with different optical paths, which can recombine different optical paths according to different concentrations of the target species, and the adjusting range is 0.5mm-100mm. When the concentration of the target species is relatively large, the optical path is adjusted to be small, so that the total amount of the target species transmitted by the monochromatic light is relatively small; when the concentration of the target species is relatively small, the optical path is adjusted to be large, so that the total amount of the target species transmitted by the monochromatic light is relatively large. By adjusting the light absorption intensity of the target species in this way, the monochromatic light received by the multi-species perception module meets the following conditions:

[0056] (1) Under different concentration conditions, the light absorption sensitivity ΔIa of the target species is maximum;

[0057] (2) When the target species is at the maximum concentration, the multi-species perception module receives the monochromatic light with a signal, i.e. I t > 0;

[0058] (3) When the target species is at the minimum concentration, the multi-species perception module receives the monochromatic light with attenuation, i.e. I0> I t > 0.

[0059] The multi-species perception module includes a photoreceiver and a signal amplifier, which can receive monochromatic light of different central wavelengths corresponding to different target species, transmission light intensity I t under different incident light intensities and different optical path conditions corresponding to different concentrations, and convert the received light signal into an electrical signal and amplify it to be fed back to the PLC control module in real time.

[0060] The working process of the embodiment is as follows:

[0061] S1, the PLC control module sends an instruction 1 to the monochromatic light purification module to determine the target species according to the target species valence state, morphology, phase state and concentration requirements of the upper computer;

[0062] S2, the monochromatic light purification module turns on the multi-wavelength multi-light intensity light source according to the instruction 1, rotates the multi-wavelength multi-stage filter disc, and outputs high-purity monochromatic light; the high-purity monochromatic light output at this time is referred to as output 1; at this time, the light intensity adjusting module and the sensitivity adjusting module are not put into work, and the output 1 directly reaches the multi-species perception module;

[0063] S3, the multi-species perception module measures the output 1 to obtain a measurement result, i.e., feedback 1, and sends the feedback 1 to the PLC control module;

[0064] S4, the PLC control module selects the filter of the multi-wavelength multi-stage filter disc according to the feedback 1 until the monochromatic light with the best center wavelength and spectral line bandwidth that meets the requirement of the instruction 1 is obtained; the monochromatic light at this time is referred to as the best incident light;

[0065] S5, the PLC control module sends an instruction 2 containing the minimum and maximum concentration change range of the target species to the light intensity control module;

[0066] S6, the light intensity control module dynamically adjusts the knob of the power / current stepless regulator from small to large according to the instruction 2, so that the monochromatic light purification module emits monochromatic light with different light intensities I0; the monochromatic light output at this time is referred to as output 2; at this time, the sensitivity adjusting module is not put into work, and the output 2 directly reaches the multi-species perception module;

[0067] S7, the multi-species perception module measures the output 2 to obtain a measurement result, i.e., feedback 2, and sends the feedback 2 to the PLC control module;

[0068] S8, the PLC control module adjusts the knob of the power / current stepless regulator according to the feedback 2 to form a closed-loop control until the light intensity I0 of the best incident light that meets the following conditions is obtained:

[0069] When the concentration of the target species changes between the minimum concentration and the maximum concentration, the multi-species perception module can receive the transmission signal of the best incident light, i.e., I t > 0;

[0070] S9, the PLC control module sends an instruction 3 containing the high-frequency concentration change range of the target species to the sensitivity adjusting module;

[0071] S10, the sensitivity adjusting module automatically adjusts the combination of the flow cell from small to large according to the instruction 3, so that the optical path of the monochromatic light passing through the sensitivity adjusting module changes; the monochromatic light emitted by the sensitivity adjusting module is referred to as output 3;

[0072] S11, the multi-species perception module measures the output 3 to obtain a measurement result, i.e., feedback 3, and sends the feedback 3 to the PLC control module;

[0073] S12, the PLC control module adjusts the optical path of the sensitivity adjustment module according to the feedback 3 to form a closed loop control until the optimal optical path that meets the following conditions is obtained:

[0074] (1) Under different concentration conditions, the light absorption sensitivity ΔIa of the target species is the maximum;

[0075] (2) When the target species is at the maximum concentration, the monochromatic light received by the multi-species perception module has a signal, that is, I t > 0;

[0076] (3) When the target species is at the minimum concentration, the monochromatic light received by the multi-species perception module has attenuation, that is, I0> I t > 0.

[0077] The specific measurement case is as follows:

[0078] After the host computer issues an instruction to measure the Cu 2+ concentration, the PLC control module issues an instruction 1 to the monochromatic light purification module to measure Cu 2+ , the multi-wavelength and multi-intensity light source of the monochromatic light purification module emits composite light of 180-900nm, the multi-wavelength and multi-stage filter disc rotates to the filter with a central wavelength of 810nm and a spectral line bandwidth of 0.03nm, and outputs monochromatic light with a wavelength of λ i = 810nm ± 0.03nm;

[0079] The PLC control module issues an instruction to the light intensity control module to measure the Cu 2+ concentration of 100-40000mg / L, and the light intensity control module dynamically adjusts the P-I parameters of the power / current stepless regulator until the light intensity I0> I 2+ of the monochromatic light when the Cu a concentration changes in the range of 100-40000mg / L; at this time, the P-I parameters are: P=5mW, I=42mA;

[0080] The PLC control module issues an instruction 3 to the sensitivity adjustment module to measure the Cu 2+ concentration of 20000-40000mg / L, and the sensitivity adjustment module automatically adjusts the optical path of the flow cell, and the signal of the monochromatic light transmitted through the flow cell is fed back to the PLC control module by the multi-species perception module until the optimal optical path condition is determined. When the optical path is 5mm, I 2+ > 0 when the Cu t concentration is the maximum, and I0> I 2+ when the Cu t concentration is the minimum.

[0081] Although embodiments of the present application have been disclosed in connection with the above specification and drawings it will be understood that they are not limited to the specific details of the foregoing description, since various changes, modifications and substitutions can be made therein without departing from the spirit and scope of the present application as defined in the following claims.

Claims

1. A kind of optical assembly for real-time direct measurement of high-concentration liquid original valence state original morphological state original phase state, characterized by: It comprises a PLC control module, a monochromatic light purification module, a light intensity control module, a sensitivity adjustment module and a multi-species perception module. The monochromatic light purification module comprises a power switch, a power adapter, a multi-wavelength multi-light intensity light source and a multi-wavelength multi-stage filter disc; the power switch and the power adapter convert 220V AC power into 5V / 2A DC power to power the multi-wavelength multi-light intensity light source; the multi-wavelength multi-light intensity light source emits composite light. The multi-wavelength multi-stage filter disc comprises a filter disc (1), a filter (2) and a servo motor (3); the filter disc (1) is provided with a circular hole, the number of which is not less than 2; the filter (2) is installed on the circular hole; the center wavelength and spectral line bandwidth of the filter (2) in different circular holes are different; the filter disc (1) has a total of 2; the circular holes of the two filter discs (1) are one-to-one corresponding and coinciding, and the center wavelengths and spectral line bandwidths of the filters (2) installed on the two coinciding circular holes are different; The composite light emitted by the multi-wavelength multi-light intensity light source passes through the two filters (2) on the circular holes of the multi-wavelength multi-stage filter disc in turn and becomes monochromatic light; The two filter discs (1) are fixedly connected with the servo motor (3) to form a whole; under the drive of the servo motor (3), the two filter discs (1) make circular motion around their own central axes, so that different circular holes and filters (2) move in front of the composite light to filter monochromatic light with different center wavelengths; The incident light intensity of monochromatic light is defined as I0, and the absorbed light intensity absorbed by the target species is defined as I a The transmitted intensity transmitted from the target species to the multi-species perception module is defined as I t That is, I0=I a +I t ; The light intensity control module comprises a power / current stepless regulator; the PLC control module adjusts the knob of the power / current stepless regulator to change the I0 of the monochromatic light and meet the following conditions: When the concentration of the target species varies between a minimum and a maximum value, the monochromatic light, after being attenuated by absorption by the target species, is still received by the multispecies perception module as a signal, i.e. I t > 0; The sensitivity adjustment module is composed of flow cells with different optical paths and adjusts different optical paths according to different concentrations of target species; when the concentration of the target species is relatively large, the optical path is adjusted to be small, so that the total amount of the target species transmitted by the monochromatic light is relatively small; when the concentration of the target species is relatively small, the optical path is adjusted to be large, so that the total amount of the target species transmitted by the monochromatic light is relatively large; finally, the monochromatic light received by the multi-species perception module meets the following conditions: (1) Under different concentration conditions, the light absorption sensitivity ΔIa of the target species is maximum; (2) When the target species is at the maximum concentration, the monochromatic light received by the multi-species perception module has a signal, i.e. I t > 0; (3) The single color light received by the multi-species perception module is attenuated when the target species is at the minimum concentration, i.e., I0> I t > 0; The multi-species sensing module comprises a photoelectric receiver and a signal amplifier, receives monochromatic light of different central wavelengths corresponding to different target species, and transmits light intensity I under different light path conditions corresponding to different concentrations t And the received light signal is converted into an electric signal and amplified, and then fed back to the PLC control module in real time. 2.The optical assembly for real-time direct measurement of high-concentration liquid original valence state original morphological state original phase state according to claim 1, characterized by: The wavelength range of the composite light is 180-900nm; The spectral line bandwidth of the filter (2) is ±0.03nm; The optical path range of the sensitivity adjustment module is 0.5mm-100mm.

3. A real-time in-situ optical assembly for measuring high concentration liquid in its original state, original form and original phase according to claim 1, characterized in that, The working process is as follows: S1, the PLC control module sends instruction 1 to measure the target species to the monochromatic light purification module according to the target species valence state morphological state concentration demand of the upper computer; S2, the monochromatic light purification module turns on the multi-wavelength multi-light intensity light source according to instruction 1, rotates the multi-wavelength multi-stage filter disc and outputs high-purity monochromatic light; the high-purity monochromatic light output at this time is called output 1. At this time, the light intensity adjustment module and the sensitivity adjustment module are not put into work, and output 1 directly reaches the multi-species perception module; S3, the multi-species perception module measures output 1 to obtain a measurement result, i.e. feedback 1, and sends the feedback 1 to the PLC control module; S4, the PLC control module selects a filter (2) of the multi-wavelength multi-stage filter disc according to the feedback 1 until a monochromatic light with an optimal central wavelength and a spectral line bandwidth meeting the requirements of the instruction 1 is obtained; the monochromatic light at this time is referred to as optimal incident light; S5, the PLC control module sends an instruction 2 containing the minimum and maximum concentration change range of the target species to the light intensity control module; S6, the light intensity control module dynamically adjusts the knob of the power / current stepless regulator from small to large according to the instruction 2, so that the monochromatic light purification module emits monochromatic light with different light intensities I0; the monochromatic light output at this time is referred to as output 2; at this time, the sensitivity adjustment module is not put into work, and output 2 directly reaches the multi-species perception module; S7, the multi-species perception module measures output 2 to obtain a measurement result, i.e. feedback 2, and sends the feedback 2 to the PLC control module; S8, the PLC control module adjusts the knob of the power / current stepless regulator according to the feedback 2 to form a closed-loop control until the optimal incident light with the light intensity I0 meeting the following conditions is obtained: When the concentration of the target species varies between a minimum concentration and a maximum concentration, the multispecies perception module receives a transmission signal of the optimal incident light, i.e. I t > 0; S9, the PLC control module sends an instruction 3 containing the high-frequency concentration change range of the target species to the sensitivity adjustment module; S10, the sensitivity adjustment module automatically adjusts the combination of the flow cell from small to large according to the instruction 3, so that the optical path of the monochromatic light passing through the sensitivity adjustment module changes; the monochromatic light emitted by the sensitivity adjustment module is referred to as output 3; S11, the multi-species perception module measures output 3 to obtain a measurement result, i.e. feedback 3, and sends the feedback 3 to the PLC control module; S12, the PLC control module adjusts the optical path of the sensitivity adjustment module according to the feedback 3 to form a closed-loop control until the optimal optical path meeting the following conditions is obtained: (1) Under different concentration conditions, the light absorption sensitivity ΔIa of the target species is maximum; (2) When the target species is at the maximum concentration, the monochromatic light received by the multi-species perception module has a signal, i.e., I t ＞0； (3) The multi-species perception module receives attenuated monochromatic light, i.e., I0> I, when the target species is at the minimum concentration. t > 0.

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