Residual chlorine and total chlorine concentration detector and detection method based on PDP spectrophotometry

Abstract

The invention provides a residual chlorine and total chlorine concentration detector based on PDP spectrophotometry and a detection method, and relates to the technical field of residual chlorine and total chlorine concentration detectors, the residual chlorine and total chlorine concentration detector comprises a shell, a sample introduction device is arranged on the left side in the shell, a detection device is arranged on the right side of the sample introduction device, and the detection device is located on the right side of the shell; the sampling device comprises a mixing cylinder for mixing samples; during use, the flow is controlled by a peristaltic pump in the sample introduction device, a variable frequency motor of the stirring assembly drives a stirring shaft to mix a sample and a reagent, and the temperature of the sample is rapidly adjusted by a semiconductor chilling plate and an exhaust unit in cooperation with the temperature adjusting assembly, so that the detection conditions are guaranteed; the switching assembly driven by the stepping motor in the detection device rapidly switches the optical filter, and the optical detector accurately captures the optical signal, so that the high efficiency and stability of the whole detection process are ensured, the tedious steps of manual operation are reduced, the detection efficiency is improved, and great convenience is provided for a user in residual chlorine and total chlorine concentration detection work.

Description

Technical Field

[0001] The invention relates to the technical field of residual chlorine and total chlorine concentration detectors, in particular to a residual chlorine and total chlorine concentration detector and a detection method based on a PDP photometric method. Background Art

[0002] The residual chlorine and total chlorine concentration detector is a professional instrument used to accurately measure the residual chlorine and total chlorine content in water. It realizes detection through specific chemical reactions combined with optical or electrochemical principles. In optical detection, residual chlorine or total chlorine reacts with reagents to generate colored compounds. The instrument converts the concentration value by measuring the degree of absorption of the compound to light of a specific wavelength based on the Lambert-Beer law. Electrochemical detection uses the current or potential changes generated by the electrochemical reaction between electrodes and residual chlorine and total chlorine to determine the concentration. The instrument is widely used in water plants, sewage treatment plants, swimming pools, food and beverage industry, medical institutions and other scenarios, and is of great significance to ensuring water quality safety and evaluating disinfection effects.

[0003] However, due to differences in production and software program usage among manufacturers, some instruments, although equipped with user self-calibration functions and capable of displaying absorbance (Abs) values, can only display absorbance values ​​and are unable to simultaneously display the transmittance and concentration of residual chlorine and total chlorine. This brings inconvenience to users in obtaining comprehensive detection information and also limits the effectiveness of the instrument to a certain extent. Summary of the invention

[0004] The purpose of the present invention is to provide a residual chlorine and total chlorine concentration detector and a detection method based on the PDP photometry, aiming to solve the problem that some instruments in the prior art have a user self-calibration function and can display the absorbance (Abs) value, but can only display the absorbance value and cannot simultaneously display the transmittance and concentration of the residual chlorine and total chlorine.

[0005] To achieve the above object, the present invention adopts the following technical solution: The residual chlorine and total chlorine concentration detector based on the PDP photometric method comprises a shell, a sampling device is arranged on the left side of the shell, a detection device is arranged on the right side of the sampling device, and the detection device is located on the right side of the shell. The sampling device comprises a mixing cylinder for mixing samples, a temperature regulating component is arranged inside the mixing cylinder, the detection device comprises a filter for switching different wavelengths, a stirring component is arranged above the mixing cylinder, the mixing cylinder adds and regulates reagents through the sampling device, the stirring component and the temperature regulating component, and the detection device also comprises a switching component, the switching component is located below the filter, and the switching component is used to regulate different filters.

[0006] Preferably, an ARM microcontroller is fixedly connected to the upper surface of the shell, a partition plate is fixedly connected to the inner wall of the shell, the outer surface of the mixing barrel is fixedly connected to the inner wall of the partition plate, the outer surface of the mixing barrel is fixedly connected to two support plates, the outer surface of each of the support plates is fixedly connected to the inner wall of the shell, a sealing cover is clamped inside the mixing barrel, the inner wall of the sealing cover and the inner wall of the mixing barrel are threadedly connected with five fixing bolts, an addition tube is clamped together with the inner wall of the shell and the inner wall of the mixing barrel, and a card cover is clamped inside the addition tube.

[0007] Preferably, the sampling device includes an adding cylinder, the outer surface of which is etched with a plurality of scale lines, the bottom surface of the adding cylinder and the outer surface of the shell are fixedly connected to an inlet pipe, the outer surface of the inlet pipe is fixedly connected to an electric valve, the upper surface of the partition plate is fixedly connected to a peristaltic pump, the input end and the output end of the peristaltic pump are respectively fixedly connected to an extraction pipe and a discharge pipe, one end of the extraction pipe passes through the interior of the mixing cylinder, the stirring assembly includes a variable frequency motor, the top end of the variable frequency motor is fixedly connected to the inner wall of the shell, the output end of the variable frequency motor is fixedly connected to a transmission rod, the outer surface of the transmission rod is fixedly connected to a sealed bearing, the outer surface of the sealed bearing is fixedly connected to the inner wall of the sealing cover, the lower end of the transmission rod is fixedly connected to a stirring shaft, and the stirring shaft is located inside the mixing cylinder.

[0008] Preferably, the temperature regulating component includes a first airflow tube, a second airflow tube and a temperature sensor, the outer surfaces of the temperature sensor, the outer surfaces of the first airflow tube and the outer surfaces of the second airflow tube are all fixedly connected to the inner wall of the mixing cylinder, the inner wall of the mixing cylinder is fixedly connected with an isolation plate, the inner wall of the isolation plate is fixedly connected with a semiconductor refrigeration plate, one end of the first airflow tube and one end of the second airflow tube are fixedly connected with a first air inlet pipe and a second air inlet pipe respectively, the isolation plate divides the bottom space of the mixing cylinder into a heating chamber and a refrigeration chamber, the first air inlet pipe and the second air inlet pipe are respectively located in the heating chamber and the refrigeration chamber, an exhaust unit is provided at the bottom of the mixing cylinder, the exhaust unit is located at the bottom of the temperature control unit, the exhaust unit includes an air pump, the output end of the air pump is fixedly connected with a protective mesh cover, the outer surface of the protective mesh cover is fixedly connected to the inner wall of the shell, the outer surface of the input end of the air pump is fixedly connected with a first exhaust pipe, and the air pump The input end is fixedly connected with a second exhaust pipe, one end of the second exhaust pipe and one end of the first exhaust pipe both pass through the interior of the mixing cylinder, one end of the second exhaust pipe and one end of the first exhaust pipe are respectively located in the heating chamber and the refrigeration chamber, the outer surface of the second exhaust pipe and the outer surface of the first exhaust pipe are fixedly connected with a first solenoid valve, the inner wall of the mixing cylinder is fixedly connected with two second solenoid valves, the two second solenoid valves are respectively connected to the heating chamber and the refrigeration chamber, the inner wall of the mixing cylinder is fixedly connected with the first circulation pipe and the second circulation pipe, one end of the first circulation pipe and one end of the second circulation pipe are respectively located in the heating chamber and the refrigeration chamber, the other end of the first circulation pipe and the other end of the second circulation pipe are respectively fixedly connected to the inner wall of the first airflow pipe and the inner wall of the second airflow pipe, the outer surface of the first circulation pipe and the outer surface of the second circulation pipe are fixedly connected with a fixed shell, and the inner wall of each of the fixed shells is fixedly connected with a micro fan.

[0009] Preferably, the detection device includes a signal processing circuit board and a tungsten filament lamp, the bottom surface of the signal processing circuit board and the top of the tungsten filament lamp are fixedly connected to the inner wall of the shell, the upper surface of the signal processing circuit board is respectively fixedly connected with a display screen, an integrated amplifier, an analog-to-digital converter and a microprocessor, the right side surface of the partition plate and the inner wall of the shell are jointly fixedly connected with a stabilizing frame, the inner wall of the stabilizing frame is fixedly connected with an absorption pool, the absorption pool is located below the filter, a light detector is arranged below the absorption pool, the outer surface of the light detector is fixedly connected with a stabilizing frame, the upper surface of the stabilizing frame is fixedly connected to the bottom surface of the stabilizing frame, the switching component includes a stepping motor, and the shell The inner wall of the housing is fixedly connected with a bracket plate, the inner wall of the bracket plate is fixedly connected with a first ball bearing, the outer surface of the stepper motor is fixedly connected to the inner wall of the housing, the output end of the stepper motor is fixedly connected with a transmission tooth head, the outer surface of the transmission tooth head is fixedly connected to the inner ring of the first ball bearing, the inner wall of the housing is fixedly connected with an annular frame, the inner wall of the annular frame is fixedly connected with a second ball bearing, the inner ring of the second ball bearing is fixedly connected to the outer surface of the filter, the bottom surface of the filter is fixedly connected with an inner gear ring, the inner wall of the inner gear ring is meshed with the outer surface of the transmission tooth head, and one end of the discharge pipe passes through the partition plate and the absorption tank in sequence and extends to the interior of the absorption tank.

[0010] The residual chlorine and total chlorine concentration detection method based on the PDP photometric method includes the following steps: S1: When starting the test, if reagents need to be added, open the card cover on the addition tube, accurately measure the reagents according to the scale line of the addition tube, inject them into the mixing tube, and then cover the card cover. Open and close the electric valve through electric control to control the reagents to flow in through the introduction tube. If the sample and reagents need to be stirred, start the variable frequency motor, and its transmission rod drives the stirring shaft to rotate in the mixing tube through the sealed bearing. The operator can also adjust the speed as needed to fully mix the sample and reagents and prepare a uniform and stable mixed liquid for subsequent testing; S2: During the mixing process, the temperature sensor monitors the temperature in the mixing cylinder in real time. When heating is required, the semiconductor refrigeration plate heats, and the hot air flows through the first air inlet pipe into the first air flow pipe, circulates through the first circulation pipe, and heats the mixing cylinder. At the same time, the air pump is started, the first solenoid valve on the first air extraction pipe and the electric valve 55 located in the heating chamber are closed, and the first solenoid valve on the second air extraction pipe and the electric valve located in the refrigeration chamber are opened to discharge the cold air from the refrigeration chamber. When cooling is required, the semiconductor refrigeration plate cools, and the cold air flows through the air inlet pipe into the second air flow pipe, circulates through the second circulation pipe, and cools the mixing cylinder. At the same time, the air pump is started, the first solenoid valve on the second air extraction pipe and the electric valve 55 located in the refrigeration chamber are closed, and the first solenoid valve on the first air extraction pipe and the electric valve 55 located in the heating chamber are opened to discharge the hot air from the heating chamber, and the temperature is precisely controlled. S3: After the sample and reagent are evenly mixed and the temperature is appropriate, the peristaltic pump is started, the mixed liquid is extracted from the mixing barrel through the extraction tube, and transported to the absorption cell through the discharge tube. In the detection device, the tungsten filament lamp emits light, and the stepper motor drives the filter to switch to the required wavelength. The light enters the absorption cell through the filter. The residual chlorine and total chlorine in the mixed liquid absorb light of specific wavelengths. The photodetector receives the transmitted light and converts it into an electrical signal. After being processed by the integrated amplifier and analog-to-digital converter, the microprocessor calculates the data according to the Lambert-Beer law and the standard curve, and displays it on the display screen and ARM microcontroller.

[0011] The beneficial effects of the present invention are: When the present invention is used, by setting a sample injection device, a temperature adjustment component, a detection device and a signal processing circuit board, the problem that the existing instrument cannot detect the sample concentration and absorbance at the same time is effectively solved. The scale line of the addition cylinder in the sample injection device cooperates with the peristaltic pump to accurately control the reagent addition amount and the sample delivery amount. The stirring component driven by the variable frequency motor promotes the full mixing of the sample and the reagent. The temperature adjustment component cooperates with the semiconductor refrigeration plate and the exhaust unit to quickly adjust the mixed liquid to a temperature environment suitable for detection. In the detection device, the switching component driven by the stepper motor can quickly switch the filter and select the appropriate wavelength. Finally, the integrated amplifier, analog-to-digital converter and microprocessor on the signal processing circuit board work together. According to the Lambert-Beer law and the calibration standard curve, the absorbance, transmittance and concentration of residual chlorine and total chlorine can be synchronously displayed on the display screen, providing users with a comprehensive and accurate analysis basis, and comprehensively improving the use efficiency of the instrument. 2. When the present invention is in use, the peristaltic pump in the sampling device controls the flow rate, the variable frequency motor of the stirring component drives the stirring shaft to mix the sample and the reagent, and the temperature adjustment component uses the semiconductor refrigeration plate and the exhaust unit to quickly adjust the sample temperature to ensure the detection conditions. The switching component driven by the stepper motor in the detection device quickly switches the filter, and the light detector accurately captures the light signal to ensure the high efficiency and stability of the entire detection process, reduce the tedious steps of manual operation, improve the detection efficiency, and provide great convenience for users in the detection of residual chlorine and total chlorine concentrations. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 It is a schematic diagram of the overall structure of the present invention; Figure 2 It is a schematic diagram of the cross-sectional structure of the shell of the present invention; Figure 3 It is a schematic cross-sectional view of the mixing cylinder and the annular frame of the present invention; Figure 4 It is a detailed enlarged structural schematic diagram of the semiconductor refrigeration plate of the present invention; Figure 5 is a schematic diagram of the first airflow tube structure of the present invention; Figure 6 It is a schematic diagram of the structure of the optical filter of the present invention; Figure 7 is a schematic cross-sectional structural diagram of an inner gear ring of the present invention; Figure 8 It is a schematic diagram of the microprocessor structure of the present invention.

[0013] In the figure: 1, housing; 2, adding cylinder; 3, scale line; 4, ARM microcontroller; 5, protective mesh cover; 6, variable frequency motor; 7, adding tube; 8, card cover; 9, tungsten lamp; 10, second ball bearing; 11, ring frame; 12, filter; 13, integrated amplifier; 14, signal processing circuit board; 15, analog-to-digital converter; 16, display screen; 17, partition plate; 18, discharge pipe; 19, mixing cylinder; 20, peristaltic pump; 21, air pump; 22, extraction tube; 23, support plate; 24, fixing bolt; 25, transmission rod; 26, second air flow tube; 27, inner gear ring; 28, stabilizing frame; 29, stabilizing frame; 30. Photodetector; 31. Absorption cell; 32. Second exhaust pipe; 33. First solenoid valve; 34. First exhaust pipe; 35. First air flow pipe; 36. Stirring shaft; 37. Inlet pipe; 38. Sealed bearing; 39. Semiconductor refrigeration plate; 40. Isolation plate; 41. Electric valve; 42. First air inlet pipe; 43. Transmission gear head; 44. Support plate; 45. First ball bearing; 46. Stepper motor; 47. Microprocessor; 48. Sealing cover; 49. Temperature sensor; 50. First circulation pipe; 51. Second air inlet pipe; 52. Micro fan; 53. Fixed shell; 54. Second circulation pipe; 55. Second solenoid valve. DETAILED DESCRIPTION

[0014] The specific implementation of the present invention will be further described below in conjunction with the accompanying drawings.

[0015] Embodiment 1, this embodiment provides the residual chlorine, total chlorine concentration detector based on PDP photometry, such as Figure 1-8 As shown, it includes a shell 1, a sampling device is arranged on the left side of the interior of the shell 1, a detection device is arranged on the right side of the sampling device, and the detection device is located on the right side of the shell 1. The sampling device includes a mixing cylinder 19 for mixing samples, and a temperature adjustment component is arranged inside the mixing cylinder 19. The detection device includes a filter 12 for switching different wavelengths, and a stirring component is arranged above the mixing cylinder 19. The mixing cylinder 19 adds and regulates reagents through the sampling device, the stirring component and the temperature adjustment component. The detection device also includes a switching component, which is located below the filter 12 and is used to regulate different filters 12.

[0016] In this embodiment, the sample and reagent are first injected into the mixing cylinder 19. In the mixing cylinder 19, the stirring component stirs and mixes the sample and the reagent, and the temperature regulating component adjusts the temperature of the mixed liquid in real time to ensure that the reaction conditions are suitable. After the mixing is completed, the mixed liquid enters the detection device on the right through the extraction component. In the detection device, the switching component adjusts the filter 12 according to the detection requirements and selects the appropriate wavelength of light for subsequent detection.

[0017] Embodiment 2, on the basis of embodiment 1, as Figure 1-8 As shown, an ARM microcontroller 4 is fixedly connected to the upper surface of the shell 1, a partition plate 17 is fixedly connected to the inner wall of the shell 1, the outer surface of the mixing barrel 19 is fixedly connected to the inner wall of the partition plate 17, the outer surface of the mixing barrel 19 is fixedly connected to two support plates 23, the outer surface of each support plate 23 is fixedly connected to the inner wall of the shell 1, a sealing cover 48 is clamped inside the mixing barrel 19, the inner wall of the sealing cover 48 and the inner wall of the mixing barrel 19 are commonly threadedly connected with five fixing bolts 24, the inner wall of the shell 1 and the inner wall of the mixing barrel 19 are commonly clamped with an addition pipe 7, and the inside of the addition pipe 7 is clamped with a card cover 8.

[0018] In this embodiment, the ARM microcontroller 4 is fixed on the upper surface of the shell 1 and is responsible for the overall control and data processing. The partition plate 17 can divide the interior of the shell 1 into two functional chambers, so that the detection device and the sampling device are separated, so that the stability of their respective operations is greatly guaranteed during operation. The support plate 23 is used to fix the mixing barrel 19 to ensure its stability. When it is necessary to add reagents, open the card cover 8, and the reagents enter the mixing barrel 19 from the addition tube 7. After the addition is completed, cover the card cover 8. The sealing cover 48 is installed on the mixing barrel 19 by the fixing bolts 24 to play a sealing role to prevent liquid leakage or external impurities from entering during the mixing process.

[0019] Embodiment 3, on the basis of embodiment 2, as Figure 1-8 As shown, the sampling device includes an addition barrel 2, the outer surface of which is etched with a plurality of scale lines 3, the bottom surface of the addition barrel 2 and the outer surface of the shell 1 are fixedly connected with an introduction pipe 37, the outer surface of the introduction pipe 37 is fixedly connected with an electric valve 41, the upper surface of the partition plate 17 is fixedly connected with a peristaltic pump 20, the input end and the output end of the peristaltic pump 20 are respectively fixedly connected with an extraction pipe 22 and a discharge pipe 18, one end of the extraction pipe 22 passes through the interior of the mixing barrel 19, the stirring assembly includes a variable frequency motor 6, the top end of the variable frequency motor 6 is fixedly connected to the inner wall of the shell 1, the output end of the variable frequency motor 6 is fixedly connected with a transmission rod 25, the outer surface of the transmission rod 25 is fixedly connected with a sealed bearing 38, the outer surface of the sealed bearing 38 is fixedly connected to the inner wall of the sealing cover 48, the lower end of the transmission rod 25 is fixedly connected with a stirring shaft 36, and the stirring shaft 36 is located inside the mixing barrel 19.

[0020] In this embodiment, the amount of sample in the addition cylinder 2 can be observed according to the scale line 3, and the electric valve 41 is opened by electric control, and the sample flows into the mixing cylinder 19 through the inlet pipe 37. After the inflow is completed, the electric valve 41 is closed by electric control, and the transmission rod 25 at the output end of the variable frequency motor 6 drives the stirring shaft 36 to rotate in the mixing cylinder 19 through the sealed bearing 38 to stir the mixed liquid. The speed of the variable frequency motor 6 can be adjusted according to actual needs to achieve the best stirring effect. If the sample does not need to be stirred, it directly enters the next process link. When detection is required, the peristaltic pump 20 draws liquid from the mixing cylinder 19 through the extraction tube 22, and then transports it to the detection device through the discharge tube 18 for detection.

[0021] Embodiment 4, on the basis of embodiment 3, as Figure 1-8 As shown, the temperature adjustment component includes a first airflow tube 35, a second airflow tube 26 and a temperature sensor 49. The outer surfaces of the temperature sensor 49, the outer surfaces of the first airflow tube 35 and the outer surfaces of the second airflow tube 26 are fixedly connected to the inner wall of the mixing cylinder 19. The inner wall of the mixing cylinder 19 is fixedly connected to an isolation plate 40. The inner wall of the isolation plate 40 is fixedly connected to a semiconductor cooling sheet 39. One end of the first airflow tube 35 and one end of the second airflow tube 26 are respectively fixedly connected to a first air inlet pipe 42 and a second air inlet pipe 51. The plate 40 divides the bottom space of the mixing cylinder 19 into a heating chamber and a cooling chamber. The first air inlet pipe 42 and the second air inlet pipe 51 are respectively located in the heating chamber and the cooling chamber. An exhaust unit is provided at the bottom of the mixing cylinder 19. The exhaust unit is located at the bottom of the temperature control unit. The exhaust unit includes an air pump 21. The output end of the air pump 21 is fixedly connected to a protective mesh cover 5. The outer surface of the protective mesh cover 5 is fixedly connected to the inner wall of the shell 1. The outer surface of the input end of the air pump 21 is fixedly connected to the first exhaust pipe 34. The input end of the air pump 21 is fixedly connected to the first exhaust pipe 34. The second exhaust pipe 32 is connected, one end of the second exhaust pipe 32 and one end of the first exhaust pipe 34 are both passed through the interior of the mixing cylinder 19, one end of the second exhaust pipe 32 and one end of the first exhaust pipe 34 are respectively located in the heating chamber and the refrigeration chamber, the outer surface of the second exhaust pipe 32 and the outer surface of the first exhaust pipe 34 are fixedly connected with the first solenoid valve 33, the inner wall of the mixing cylinder 19 is fixedly connected with two second solenoid valves 55, the two second solenoid valves 55 are respectively connected to the heating chamber and the refrigeration chamber, and the inner wall of the mixing cylinder 19 is fixedly connected with the second solenoid valve 55. The walls are fixedly connected with a first circulation pipe 50 and a second circulation pipe 54, one end of the first circulation pipe 50 and one end of the second circulation pipe 54 are respectively located in the heating chamber and the refrigeration chamber, the other end of the first circulation pipe 50 and the other end of the second circulation pipe 54 are respectively fixedly connected to the inner wall of the first airflow pipe 35 and the inner wall of the second airflow pipe 26, the outer surface of the first circulation pipe 50 and the outer surface of the second circulation pipe 54 are fixedly connected with a fixed shell 53, and the inner wall of each fixed shell 53 is fixedly connected with a micro fan 52.

[0022] In this embodiment, the temperature sensor 49 can detect the internal temperature of the mixing cylinder 19, and its outer surface is fixedly connected to the inner wall of the mixing cylinder 19, providing real-time data for the subsequent precise regulation of the internal temperature of the mixing cylinder 19 by the temperature adjustment component, thereby ensuring the sample testing environment. The two second solenoid valves 55 opened on the outer surface of the mixing cylinder 19 are connected to the heating chamber and the cooling chamber respectively, which can ensure smooth ventilation inside the heating chamber and the cooling chamber, maintain the air pressure balance in the chamber, and ensure that the heating and cooling processes are stable and efficient. When the reagent inside the mixing cylinder 19 needs to be heated, the second solenoid valve 55 located inside the heating chamber is closed, and the semiconductor refrigeration sheet 39 is directly used for heating. The semiconductor refrigeration sheet 39 has one end for cooling and the other end for heating. The indoor and refrigeration chambers correspond to the first exhaust pipe 34 and the second exhaust pipe 32 respectively. In the heating chamber, the hot air flows into the first air flow pipe 35 through the first air inlet pipe 42. The first air inlet pipe 42 is specifically responsible for introducing the hot air flow into the first air flow pipe 35. Since the first air flow pipe 35 is in contact with the inner wall of the mixing cylinder 19, the surface of the mixing cylinder 19 can be heated, and then the sample inside the mixing cylinder 19 is heated by heat transfer. At the same time, one end of the first circulation pipe 50 fixedly connected to the inner wall of the mixing cylinder 19 is located in the heating chamber, and the other end is fixedly connected to the inner wall of the first air flow pipe 35. The micro-blower 52 in the fixed shell 53 on its outer surface is started to continuously transport the hot air in the first circulation pipe 50 to the first air flow pipe 35, so that the hot air is heated in the first air flow pipe 3 5 internal circulation, further enhancing the heating effect, at the same time, start the air pump 21, close the first electromagnetic valve 33 on the first exhaust pipe 34, and open the first electromagnetic valve 33 on the second exhaust pipe 32 and the second electromagnetic valve 55 located inside the refrigeration chamber, so that the external air circulates with the refrigeration chamber to maintain pressure balance, and use the air pump 21 to extract the cold air inside the refrigeration chamber through the second exhaust pipe 32 to prevent the cold air from entering the second air flow pipe 26 through the first air inlet pipe 42. The extracted cold air is directly discharged to the outside of the shell 1 through the protective net cover 5. On the contrary, when the reagent inside the mixing cylinder 19 needs to be refrigerated, close the second electromagnetic valve 55 located in the refrigeration chamber, and directly use the semiconductor refrigeration sheet 39 for refrigeration. In the chamber, the cold air flow enters the second air flow tube 26 through the second air inlet pipe 51. The function of the second air inlet pipe 51 is to introduce the cold air flow into the second air flow tube 26. Since the second air flow tube 26 is also in contact with the inner wall of the mixing cylinder 19, it can realize refrigeration and cooling of the surface of the mixing cylinder 19, and effectively refrigerate the sample inside the mixing cylinder 19. At this time, one end of the second circulation tube 54 is located in the refrigeration chamber, and the other end is fixedly connected to the inner wall of the second air flow tube 26. The micro fan 52 in the fixed shell 53 on its outer surface transports the cold air in the second circulation tube 54 to the second air flow tube 26, so that the cold air circulates in the second air flow tube 26 for continuous refrigeration. At the same time, during the refrigeration process, the air pump 21 is started, and the first solenoid valve 33 on the second exhaust pipe 32 is closed.At the same time, the first solenoid valve 33 on the first air extraction pipe 34 and the second solenoid valve 55 located inside the heating chamber are opened to facilitate the circulation of air between the heating chamber and the outside, maintain pressure balance, and use the air pump 21 to extract the hot air inside the heating chamber through the first air extraction pipe 34 to prevent the hot air from entering the first air flow pipe 35 through the first air inlet pipe 42. The extracted hot air is directly discharged to the outside of the housing 1 through the protective mesh cover 5, which greatly improves the ability to accurately control the temperature of the mixed liquid in the mixing cylinder 19.

[0023] Embodiment 5, on the basis of embodiment 4, as Figure 1-8 As shown, the detection device includes a signal processing circuit board 14 and a tungsten filament lamp 9, the bottom surface of the signal processing circuit board 14 and the top of the tungsten filament lamp 9 are fixedly connected to the inner wall of the shell 1, the upper surface of the signal processing circuit board 14 is respectively fixedly connected with a display screen 16, an integrated amplifier 13, an analog-to-digital converter 15 and a microprocessor 47, the right side surface of the partition plate 17 and the inner wall of the shell 1 are jointly fixedly connected with a stabilizing frame 28, the inner wall of the stabilizing frame 28 is fixedly connected with an absorption pool 31, the absorption pool 31 is located below the filter 12, and a light detector 30 is arranged below the absorption pool 31, the outer surface of the light detector 30 is fixedly connected with a stabilizing frame 29, the upper surface of the stabilizing frame 29 is fixedly connected to the bottom surface of the stabilizing frame 28, the switching component includes a stepping motor 46, and the shell 1 A bracket plate 44 is fixedly connected to the inner wall, a first ball bearing 45 is fixedly connected to the inner wall of the bracket plate 44, an outer surface of a stepper motor 46 is fixedly connected to the inner wall of the shell 1, a transmission gear head 43 is fixedly connected to the output end of the stepper motor 46, an outer surface of the transmission gear head 43 is fixedly connected to the inner ring of the first ball bearing 45, an annular frame 11 is fixedly connected to the inner wall of the shell 1, a second ball bearing 10 is fixedly connected to the inner wall of the annular frame 11, an inner ring of the second ball bearing 10 is fixedly connected to the outer surface of the filter 12, an inner gear ring 27 is fixedly connected to the bottom surface of the filter 12, an inner wall of the inner gear ring 27 is meshed with an outer surface of the transmission gear head 43, one end of the discharge pipe 18 passes through the partition plate 17 and the absorption tank 31 in sequence and extends to the interior of the absorption tank 31.

[0024] In this embodiment, the tungsten lamp 9 emits light to operate the stepper motor 46. The transmission gear head 43 at the output end of the stepper motor 46 meshes with the inner gear ring 27, driving the filter 12 to rotate and switch to the filter 12 of the required wavelength. After passing through the filter 12, the light enters the absorption cell 31 and reacts with the mixed liquid entering the absorption cell 31 from the discharge pipe 18. The residual chlorine and total chlorine in the mixed liquid absorb the light of a specific wavelength. The light detector 30 receives the light passing through the absorption cell 31 and converts the optical signal into an electrical signal. The electrical signal is transmitted to the signal processing circuit board 14. The integrated amplifier 13 amplifies the signal. The analog-to-digital converter 15 converts the analog signal into a digital signal. The microprocessor 47 calculates the absorbance, transmittance and concentration of the residual chlorine and the total chlorine according to the Lambert-Beer law and the pre-calibrated standard curve. Finally, the detection result is displayed on the display screen 16. The result can be directly displayed on the ARM microcontroller 4 through the electrical signal, which is convenient for the detection personnel to watch. At the same time, when it is necessary to clean the internal parts, the two protective doors on the housing 1 can be directly opened for cleaning to prevent clogging by impurities.

[0025] Working principle: when it is necessary to add reagents, open the card cover 8 on the adding tube 7, and inject the reagents into the mixing barrel 19. After the injection is completed, cover the card cover 8 to prevent external impurities from mixing in and reagents from leaking, ensuring that the mixing process is not disturbed. If it is not necessary to add reagents, there is no need to open the card cover 8. The ARM microcontroller 4 is fixedly installed on the top of the shell 1 to provide intelligent regulation for the entire detection process to ensure that all links are closely coordinated and run in an orderly manner. When it is necessary to add samples, the operator can accurately observe the amount of the sample based on the clearly etched scale lines 3 on the outer surface of the adding barrel 2. After confirmation, the electric valve 41 is opened through the electric control, and the sample will flow smoothly into the mixing barrel 19 through the introduction tube 37. After the sample flows in, it is opened again through the electric control The electric valve 41 is controlled to be closed to avoid unnecessary waste of samples and the influence of external factors. If the sample and the reagent need to be fully stirred and mixed, it is only necessary to start the variable frequency motor 6. After the motor is started, the transmission rod 25 at its output end will drive the stirring shaft 36 to rotate at high speed in the mixing barrel 19 with the help of the sealed bearing 38. The operator can also flexibly adjust the speed of the variable frequency motor 6 according to the actual detection needs, so as to achieve the best stirring effect, so that the sample and the reagent are fully integrated, and a uniform and stable mixed liquid is provided for subsequent detection. During the entire mixing process, the temperature sensor 49 can detect the internal temperature of the mixing barrel 19, and its outer surface is fixedly connected to the inner wall of the mixing barrel 19, so as to provide real-time data for the subsequent precise control of the internal temperature of the mixing barrel 19 by the temperature adjustment component, thereby ensuring Sample testing environment, two second solenoid valves 55 opened on the outer surface of the mixing cylinder 19 are connected to the heating chamber and the refrigeration chamber respectively, which can ensure smooth ventilation inside the heating chamber and the refrigeration chamber, maintain the air pressure balance in the chamber, and ensure that the heating and cooling processes are stable and efficient. When the reagent inside the mixing cylinder 19 needs to be heated, the second solenoid valve 55 located inside the heating chamber is closed, and the semiconductor refrigeration plate 39 is directly used for heating. The semiconductor refrigeration plate 39 has one end for cooling and the other end for heating. The heating chamber and the refrigeration chamber correspond to the first exhaust pipe 34 and the second exhaust pipe 32 respectively. In the heating chamber, the hot air flow enters the first air flow pipe 35 through the first air inlet pipe 42. The first air inlet pipe 42 is specifically responsible for introducing the hot air flow into the first air flow pipe 35. Since the first air flow pipe 35 and The inner wall of the mixing cylinder 19 is in contact, so that the surface of the mixing cylinder 19 can be heated, and then the sample inside the mixing cylinder 19 is heated by heat transfer. At the same time, one end of the first circulation pipe 50 fixedly connected to the inner wall of the mixing cylinder 19 is located in the heating chamber, and the other end is fixedly connected to the inner wall of the first air flow pipe 35. The micro-blower 52 in the fixed shell 53 on the outer surface is started to continuously transport the hot air in the first circulation pipe 50 to the first air flow pipe 35, so that the hot air circulates inside the first air flow pipe 35, further enhancing the heating effect. At the same time, the air pump 21 is started, the first solenoid valve 33 on the first exhaust pipe 34 is closed, and the first solenoid valve 33 on the second exhaust pipe 32 and the second solenoid valve 55 located inside the refrigeration chamber are opened, so that the external air circulates with the refrigeration chamber.Keep the pressure balanced, use the air pump 21 to extract the cold air inside the refrigeration chamber through the second exhaust pipe 32, prevent the cold air from entering the second air flow pipe 26 through the first air inlet pipe 42, and the extracted cold air is directly discharged to the outside of the shell 1 through the protective mesh cover 5. On the contrary, when the reagent inside the mixing cylinder 19 needs to be refrigerated, close the second solenoid valve 55 located in the refrigeration chamber, and directly use the semiconductor refrigeration plate 39 for refrigeration. In the refrigeration chamber, the cold air flow enters the second air flow pipe 26 through the second air inlet pipe 51. The function of the second air inlet pipe 51 is to introduce the cold air flow into the second air flow pipe 26. Since the second air flow pipe 26 is also in contact with the inner wall of the mixing cylinder 19, it can achieve refrigeration and cooling of the surface of the mixing cylinder 19, and effectively refrigerate the sample inside the mixing cylinder 19. At this time, one end of the second circulation pipe 54 is located in the refrigeration chamber, and the other end is fixedly connected to the inner wall of the second airflow pipe 26. The micro-blower 52 in the fixed shell 53 on its outer surface transports the cold air in the second circulation pipe 54 to the second airflow pipe 26, so that the cold air circulates in the second airflow pipe 26 to continuously cool. At the same time, during the refrigeration process, the air pump 21 is started, the first solenoid valve 33 on the second air extraction pipe 32 is closed, and the first solenoid valve 33 on the first air extraction pipe 34 and the second solenoid valve 55 located inside the heating chamber are opened at the same time, so as to facilitate the circulation of air between the heating chamber and the outside and maintain pressure balance. The air pump 21 is used to extract the hot air inside the heating chamber through the first air extraction pipe 34 to prevent the hot air from entering the first airflow pipe 35 through the first air inlet pipe 42 The extracted hot air is directly discharged to the outside of the shell 1 through the protective mesh cover 5, which greatly improves the ability to accurately control the temperature of the mixed liquid in the mixing cylinder 19, ensuring that the reaction conditions required for the test are suitable. After the sample and the reagent are fully mixed and the temperature is adjusted to a suitable range, the peristaltic pump 20 is started, and the mixed liquid is accurately extracted from the mixing cylinder 19 through the extraction tube 22, and then the mixed liquid is smoothly transported to the absorption pool 31 on the right through the discharge tube 18. In the detection device, the tungsten lamp 9 emits light, and then, according to the needs, the appropriate filter 12 is adjusted, and the stepper motor 46 is operated. The transmission gear head 43 at the output end will be tightly engaged with the inner gear ring 27, thereby driving the filter 12 to rotate, and quickly switch to the filter 12 of the required wavelength for detection. After the filter 12 is filtered The light after entering the absorption cell 31 reacts with the mixed liquid flowing in from the discharge pipe 18. At this time, the residual chlorine and total chlorine in the mixed liquid will absorb the light of a specific wavelength. The light detector 30 is located below the absorption cell 31 and is responsible for receiving the light passing through the absorption cell 31 and quickly converting the received light signal into an electrical signal. These electrical signals are then transmitted to the signal processing circuit board 14. On the circuit board, the integrated amplifier 13 first amplifies the signal to enhance the signal strength for subsequent processing. Then, the analog-to-digital converter 15 converts the amplified analog signal into a digital signal to facilitate the microprocessor 47 to perform accurate calculations. The microprocessor 47 performs in-depth analysis and calculations on the digital signal based on the Lambert-Beer law and the pre-calibrated standard curve.Finally, the key data such as the absorbance, transmittance and concentration of residual chlorine and total chlorine are obtained. Finally, these data embodying the test results will be intuitively displayed on the display screen 16, and the test personnel can obtain the test results at a glance. At the same time, the data will be directly transmitted to the ARM microcontroller 4 through electrical signals for display, providing test personnel with multiple viewing methods to facilitate data recording, analysis and comparison. After the instrument has been used for a period of time, in order to ensure that it is always in good working condition and prevent impurities from clogging and affecting the detection accuracy, you only need to directly open the two protective doors on the shell 1 to clean and maintain the internal parts, ensure the stable operation of the instrument and the accuracy of the test results, and a through hole is set on the protective door on the front of the shell 1 to facilitate air circulation. ,

[0026] In combination with the above process, this scheme provides a method for detecting residual chlorine and total chlorine concentration based on PDP photometry, which specifically includes the following steps: S1: When starting the test, if reagents need to be added, open the card cover 8 on the addition tube 7, accurately measure the reagents according to the scale line 3 of the addition tube 2, inject them into the mixing tube 19, and then cover the card cover 8. Open and close the electric valve 41 through electric control to control the reagents to flow in through the introduction tube 37. If the sample and the reagent need to be stirred, start the variable frequency motor 6, and its transmission rod 25 drives the stirring shaft 36 to rotate in the mixing tube 19 through the sealed bearing 38. The operator can also adjust the speed as needed to fully mix the sample and the reagent to prepare a uniform and stable mixed solution for subsequent testing; S2: During the mixing process, the temperature sensor 49 monitors the temperature in the mixing cylinder 19 in real time. When heating is required, the semiconductor refrigeration plate 39 heats, and the hot air flows through the first air inlet pipe 42 into the first air flow pipe 35, circulates through the first circulation pipe 50, and heats the mixing cylinder 19. At the same time, the air pump 21 is started, the first solenoid valve 33 on the first air extraction pipe 34 and the electric valve 55 located in the heating chamber are closed, and the first solenoid valve 33 on the second air extraction pipe 32 and the electric valve 55 located in the refrigeration chamber are opened to discharge the cold air in the refrigeration chamber. When cooling is required, the semiconductor refrigeration plate 39 cools, and the cold air flows through the first air inlet pipe 42 into the second air flow pipe 26, circulates through the second circulation pipe 54, and cools the mixing cylinder 19. At the same time, the air pump 21 is started, the first solenoid valve 33 on the second air extraction pipe 32 and the electric valve 55 located in the refrigeration chamber are closed, and the first solenoid valve 33 on the first air extraction pipe 34 and the electric valve 55 located in the heating chamber are opened to discharge the hot air in the heating chamber, and the temperature is precisely controlled. S3: After the sample and reagent are evenly mixed and the temperature is appropriate, the peristaltic pump 20 is started, and the mixed liquid is extracted from the mixing cylinder 19 through the extraction tube 22, and transported to the absorption cell 31 through the discharge tube 18. In the detection device, the tungsten filament lamp 9 emits light, and the stepper motor 46 drives the filter 12 to switch to the required wavelength. The light enters the absorption cell 31 through the filter 12. The residual chlorine and total chlorine in the mixed liquid absorb light of a specific wavelength. The light detector 30 receives the transmitted light and converts it into an electrical signal. After being processed by the integrated amplifier 13 and the analog-to-digital converter 15, the microprocessor 47 calculates the data according to the Lambert-Beer law and the standard curve, and displays it on the display screen 16 and the ARM microcontroller 4.

[0027] It will be apparent to those skilled in the art that the invention is not limited to the details of the exemplary embodiments described above and that the invention can be implemented in other specific forms without departing from the spirit or essential features of the invention. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description, and it is intended that all variations falling within the meaning and scope of the equivalent elements of the claims be included in the invention. Any reference numeral in a claim should not be considered as limiting the claim to which it relates.

[0028] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. The residual chlorine and total chlorine concentration detector based on PDP photometry is characterized in that: The invention comprises a housing (1), wherein a sample injection device is arranged on the left side of the housing (1), a detection device is arranged on the right side of the sample injection device, and the detection device is located on the right side of the housing (1). The sample injection device comprises a mixing cylinder (19) for mixing samples, and a temperature adjustment component is arranged inside the mixing cylinder (19). The detection device comprises a filter (12) for switching different wavelengths, and a stirring component is arranged above the mixing cylinder (19). The mixing cylinder (19) adds and adjusts reagents through the sample injection device, the stirring component and the temperature adjustment component. The detection device also comprises a switching component, and the switching component is located below the filter (12). The switching component is used to adjust different filters (12).

2. The residual chlorine and total chlorine concentration detector based on the PDP photometry according to claim 1 is characterized in that: An ARM microcontroller (4) is fixedly connected to the upper surface of the shell (1), a partition plate (17) is fixedly connected to the inner wall of the shell (1), the outer surface of the mixing cylinder (19) is fixedly connected to the inner wall of the partition plate (17), the outer surface of the mixing cylinder (19) is fixedly connected to two support plates (23), the outer surface of each support plate (23) is fixedly connected to the inner wall of the shell (1), a sealing cover (48) is clamped inside the mixing cylinder (19), the inner wall of the sealing cover (48) and the inner wall of the mixing cylinder (19) are threadedly connected to five fixing bolts (24), the inner wall of the shell (1) and the inner wall of the mixing cylinder (19) are clamped together with an addition pipe (7), and the inside of the addition pipe (7) is clamped with a card cover (8).

3. The residual chlorine and total chlorine concentration detector based on the PDP photometry according to claim 2 is characterized in that: The sample injection device comprises an addition cylinder (2), the outer surface of the addition cylinder (2) being etched with a plurality of scale lines (3), the bottom surface of the addition cylinder (2) and the outer surface of the housing (1) being fixedly connected to an introduction tube (37), the outer surface of the introduction tube (37) being fixedly connected to an electric valve (41), the upper surface of the partition plate (17) being fixedly connected to a peristaltic pump (20), the input end and the output end of the peristaltic pump (20) being fixedly connected to an extraction tube (22) and a discharge tube (18), respectively, one end of the extraction tube (22) extending to Inside the mixing barrel (19), the stirring assembly comprises a variable frequency motor (6), the top end of the variable frequency motor (6) is fixedly connected to the inner wall of the housing (1), the output end of the variable frequency motor (6) is fixedly connected to a transmission rod (25), the outer surface of the transmission rod (25) is fixedly connected to a sealed bearing (38), the outer surface of the sealed bearing (38) is fixedly connected to the inner wall of a sealing cover (48), the lower end of the transmission rod (25) is fixedly connected to a stirring shaft (36), and the stirring shaft (36) is located inside the mixing barrel (19).

4. The residual chlorine and total chlorine concentration detector based on the PDP photometry according to claim 3 is characterized in that: The temperature regulating component comprises a first airflow tube (35), a second airflow tube (26) and a temperature sensor (49); the outer surface of the temperature sensor (49), the outer surface of the first airflow tube (35) and the outer surface of the second airflow tube (26) are all fixedly connected to the inner wall of the mixing cylinder (19); the inner wall of the mixing cylinder (19) is fixedly connected to an isolation plate (40); the inner wall of the isolation plate (40) is fixedly connected to a semiconductor cooling plate (39); one end of the first airflow tube (35) and one end of the second airflow tube (26) are respectively fixedly connected to a first air inlet tube (42) and a second air inlet tube (51); The isolation plate (40) divides the bottom space of the mixing cylinder (19) into a heating chamber and a cooling chamber. The first air inlet pipe (42) and the second air inlet pipe (51) are located in the heating chamber and the cooling chamber, respectively. An exhaust unit is provided at the bottom of the mixing cylinder (19). The exhaust unit is located at the bottom of the temperature control unit. The exhaust unit comprises an air pump (21). The output end of the air pump (21) is fixedly connected to a protective mesh cover (5). The outer surface of the protective mesh cover (5) is fixedly connected to the inner wall of the housing (1). The outer surface of the input end of the air pump (21) is fixedly connected to a first exhaust pipe (34). The air pump (21) The input end of the mixing cylinder (19) is fixedly connected to a second air extraction pipe (32), one end of the second air extraction pipe (32) and one end of the first air extraction pipe (34) both penetrate into the interior of the mixing cylinder (19), one end of the second air extraction pipe (32) and one end of the first air extraction pipe (34) are respectively located in the heating chamber and the refrigeration chamber, the outer surface of the second air extraction pipe (32) and the outer surface of the first air extraction pipe (34) are both fixedly connected to a first solenoid valve (33), the inner wall of the mixing cylinder (19) is fixedly connected to two second solenoid valves (55), the two second solenoid valves (55) are respectively connected to the heating chamber and the refrigeration chamber, and the mixing cylinder (19) 9) are respectively fixedly connected to the inner wall of the first circulation tube (50) and the second circulation tube (54), one end of the first circulation tube (50) and one end of the second circulation tube (54) are respectively located in the heating chamber and the cooling chamber, the other end of the first circulation tube (50) and the other end of the second circulation tube (54) are respectively fixedly connected to the inner wall of the first airflow tube (35) and the inner wall of the second airflow tube (26), the outer surface of the first circulation tube (50) and the outer surface of the second circulation tube (54) are both fixedly connected to a fixed shell (53), and the inner wall of each of the fixed shells (53) is fixedly connected to a micro fan (52).

5. The residual chlorine and total chlorine concentration detector based on PDP photometry according to claim 4 is characterized in that: The detection device comprises a signal processing circuit board (14) and a tungsten filament lamp (9), the bottom surface of the signal processing circuit board (14) and the top of the tungsten filament lamp (9) are fixedly connected to the inner wall of the housing (1), the upper surface of the signal processing circuit board (14) is respectively fixedly connected to a display screen (16), an integrated amplifier (13), an analog-to-digital converter (15) and a microprocessor (47), the right side surface of the partition plate (17) and the inner wall of the housing (1) are jointly fixedly connected to a stabilizing frame (28), the inner wall of the stabilizing frame (28) is fixedly connected to an absorption pool (31), the absorption pool (31) is located below the filter (12), a light detector (30) is arranged below the absorption pool (31), the outer surface of the light detector (30) is fixedly connected to a stabilizing frame (29), the upper surface of the stabilizing frame (29) is fixedly connected to the bottom surface of the stabilizing frame (28), the switching component comprises a stepping motor (46), the housing (1 ) is fixedly connected to the inner wall of the housing (1) with a support plate (44), the inner wall of the support plate (44) is fixedly connected to a first ball bearing (45), the outer surface of the stepping motor (46) is fixedly connected to the inner wall of the housing (1), the output end of the stepping motor (46) is fixedly connected to a transmission tooth head (43), the outer surface of the transmission tooth head (43) is fixedly connected to the inner ring of the first ball bearing (45), the inner wall of the housing (1) is fixedly connected to an annular frame (11), the inner wall of the annular frame (11) is fixedly connected to a second ball bearing (10), the inner ring of the second ball bearing (10) is fixedly connected to the outer surface of the filter (12), the bottom surface of the filter (12) is fixedly connected to an inner gear ring (27), the inner wall of the inner gear ring (27) is meshed with the outer surface of the transmission tooth head (43), and one end of the discharge pipe (18) passes through the partition plate (17) and the absorption pool (31) in sequence and extends to the interior of the absorption pool (31).

6. A method for detecting residual chlorine and total chlorine concentrations based on PDP photometry, using the residual chlorine and total chlorine concentration detector based on PDP photometry described in claims 1-5, characterized in that: The following steps are involved: S1: When starting the test, if it is necessary to add reagents, open the card cover (8) on the addition tube (7), accurately measure the reagents according to the scale line (3) on the addition tube (2), inject them into the mixing tube (19), and then cover the card cover (8). Open and close the electric valve (41) through electric control to control the reagents to flow in through the introduction tube (37). If the sample and the reagents need to be stirred, start the variable frequency motor (6), and its transmission rod (25) drives the stirring shaft (36) to rotate in the mixing tube (19) through the sealed bearing (38). The operator can also adjust the speed as needed to fully mix the sample and the reagents, so as to prepare a uniform and stable mixed solution for subsequent testing; S2: During the mixing process, the temperature sensor (49) monitors the temperature in the mixing cylinder (19) in real time. When heating is required, the semiconductor refrigeration plate (39) heats the mixture, and the hot air flows through the first air inlet pipe (42) into the first air flow pipe (35), circulates through the first circulation pipe (50), and heats the mixing cylinder (19). At the same time, the air pump (21) is started, the first solenoid valve (33) on the first air extraction pipe (34) and the electric valve (55) located in the heating chamber are closed, and the first solenoid valve (33) on the second air extraction pipe (32) and the electric valve (55) located in the cooling chamber are opened. ), discharges cold air from the refrigeration chamber. When refrigeration is required, the semiconductor refrigeration plate (39) performs refrigeration, and the cold air flows through the air inlet pipe (42) into the second air flow pipe (26), circulates through the second circulation pipe (54), and refrigerates the mixing cylinder (19). At the same time, the air pump (21) is started, the first solenoid valve (33) on the second air extraction pipe (32) and the electric valve (55) located in the refrigeration chamber are closed, and the first solenoid valve (33) on the first air extraction pipe (34) and the electric valve (55) located in the heating chamber are opened to discharge the hot air from the heating chamber, thereby accurately controlling the temperature; S3: After the sample and reagent are evenly mixed and the temperature is appropriate, the peristaltic pump (20) is started, and the mixed liquid is extracted from the mixing cylinder (19) through the extraction tube (22), and transported to the absorption cell (31) through the discharge tube (18). In the detection device, the tungsten filament lamp (9) emits light, and the stepper motor (46) drives the filter (12) to switch to the required wavelength. The light enters the absorption cell (31) through the filter (12). The residual chlorine and total chlorine in the mixed liquid absorb light of a specific wavelength. The light detector (30) receives the transmitted light and converts it into an electrical signal. After being processed by the integrated amplifier (13) and the analog-to-digital converter (15), the microprocessor (47) calculates the data according to the Lambert-Beer law and the standard curve, and displays it on the display screen (16) and the ARM microcontroller (4).

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