A chamber for detecting a concentration of a contaminant

Abstract

The utility model relates to the technical field of pollutant detection, and specifically discloses a kind of pollutant concentration detection room, including detection room main body, inside is equipped with sample room;Sample room entrance and sample room detection port are respectively arranged in the different side surface of detection room main body, and are closed by the window body that can be opened and closed;Air inlet and air outlet are communicated with sample room, for gas phase pollutant detection, air inlet connects the sample inlet pipeline of flowmeter;Trigger is installed at sample room entrance, for inputting light signal to sample room;Detector is installed at sample room detection port and penetrates detection room main body, for detecting sample fluorescence signal and converting into electric signal;Temperature control device is connected into detection room main body, for regulating and controlling sample room internal temperature;Data processing module is used to analyze the electric signal obtained by detector conversion, and analysis result is transmitted to data display module.The utility model is compact in structure, and detection sensitivity is high, is applicable to the rapid detection of multiple pollutants in the field such as environmental monitoring, industrial emission etc..

Description

Technical Field

[0001] This utility model relates to the field of pollutant detection technology, and in particular to a pollutant concentration detection chamber. Background Technology

[0002] In today's society, with increasing emphasis on health and environmental protection, the demand for monitoring the concentrations of pollutants such as formaldehyde and sulfur dioxide is constantly growing in the civilian, commercial, and industrial sectors. Common indoor air pollutants pose a significant threat to human health. Traditional detection methods have many limitations, such as low measurement accuracy, reliance on offline detection, and typically being designed for single pollutants, making them unsuitable for samples in different states. This not only affects the reliability of the test results but also limits the breadth and effectiveness of pollutant monitoring in practical applications. Utility Model Content

[0003] To address the shortcomings of existing technologies, this invention proposes a pollutant concentration detection chamber based on the Hantzsch fluorescence method, temperature control function, high-precision measurement, and multiphase measurability, in order to achieve high-precision, real-time, and online measurement of pollutant concentration.

[0004] To achieve the above-mentioned technical effects, one of the objectives of this utility model is to provide a pollutant concentration detection chamber, comprising:

[0005] The main body of the testing laboratory contains a sample room for storing pollutant samples;

[0006] The sample chamber entrance and sample chamber testing port are located on different sides of the main body of the testing chamber, and are enclosed by openable and closable windows.

[0007] The air inlet and outlet are connected to the sample chamber for the detection of gaseous pollutants. The air inlet is connected to the sample inlet line with a flow meter.

[0008] The trigger, installed at the sample chamber entrance, is used to input light signals into the sample chamber;

[0009] The detector is installed at the sample chamber detection port and runs through the main body of the detection chamber. It is used to detect the sample fluorescence signal and convert it into an electrical signal.

[0010] A temperature control device is connected to the main body of the detection chamber and is used to regulate the temperature inside the sample chamber;

[0011] The data processing module is used to analyze the electrical signals converted by the detector and transmit the analysis results to the data display module in data form;

[0012] The data display module is used to display pollutant concentrations in real time.

[0013] As a preferred technical solution, there are multiple detectors symmetrically distributed around the detection port of the sample chamber, and the detection end of the detector extends into the sample chamber through a detachable connector.

[0014] As a preferred technical solution, the detachable connector is cylindrical, with an opening in the center that communicates with the sample chamber detection port, and connection holes on the side wall that match the number and position of the detectors, and is detachably connected to the outer wall of the detection chamber body.

[0015] As a preferred technical solution, the trigger is selected from light-emitting diodes, laser diodes, LEDs, ultraviolet light-emitting diodes, or zinc lamps; and / or, the detector is selected from photodiodes, avalanche photodiodes, photomultiplier tubes, or optocouplers.

[0016] As a preferred technical solution, the temperature control device includes:

[0017] Temperature sensor to monitor the temperature of the sample chamber and the contaminant samples inside in real time;

[0018] The control circuit receives the temperature sensor signal and calculates the deviation value, and outputs the control command to the heating / cooling module to maintain a constant temperature environment for pollutant detection.

[0019] The heating / cooling module adjusts the sample chamber temperature according to the instructions of the control circuit.

[0020] As a preferred technical solution, the pollutant sample is formaldehyde or sulfur dioxide.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] This utility model provides a multifunctional pollutant concentration detection chamber capable of high-precision detection of pollutants such as formaldehyde and sulfur dioxide in gas or liquid phases, and has the following technical advantages:

[0023] 1) High detection accuracy:

[0024] Formaldehyde detection uses the Hantzsch fluorescence method. The stability of the DDL fluorescence reaction is ensured by a temperature control device (maintaining 60-80℃ during formaldehyde detection) and pH control. Combined with weighted least squares correction of low concentration data, the linear correlation coefficient reaches 0.9995.

[0025] Sulfur dioxide detection uses ultraviolet fluorescence method, which excites 214nm ultraviolet light at 50℃±5℃, and reduces stray light interference and improves signal-to-noise ratio by using a 230nm filter and a 90° detection angle.

[0026] 2) Precise temperature control: The temperature control device adjusts the sample chamber and detector temperature in real time to eliminate the influence of ambient temperature on fluorescence efficiency and ensure reliable measurement results.

[0027] 3) It is compatible with a variety of triggers and detectors, and can be expanded for fluorescence detection of different pollutants.

[0028] 4) After the electrical signal is amplified and the data is acquired, the algorithm automatically corrects and displays the concentration, realizing real-time online monitoring.

[0029] 5) The detection chamber adopts a split design, with the sample chamber entrance and the detection port located on different sides to avoid light signal interference; the detachable connectors facilitate the replacement of detectors and improve the adaptability of the device. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the overall structure of the pollutant concentration detection chamber of this utility model;

[0031] Figure 2 This is a flowchart of the pollutant concentration detection method of this utility model;

[0032] Figure 3 The graph shows the effect of reaction temperature on the fluorescence intensity of formaldehyde at different concentrations.

[0033] Figure 4 The graph shows the effect of reaction time on the fluorescence intensity of formaldehyde at the same concentration.

[0034] Figure 5 The fluorescence intensity emission spectrum;

[0035] Figure 6 The graph shows the relationship between formaldehyde content and DDL absorbance.

[0036] Figure 7 This is a graph showing the relationship between formaldehyde concentration and fluorescence intensity.

[0037] Figure 8 This is a graph showing the relationship between sulfur dioxide concentration and voltage signal intensity.

[0038] Figure 9 The effect of reaction temperature on the average concentration of standard gas measurements;

[0039] Figure 10 This reflects the effect of temperature on the average error between the measurement results and the standard value.

[0040] In the picture:

[0041] 1. Trigger; 2. Detector; 3. Sample chamber entrance; 4. Sample chamber detection port; 5. Connector; 6. Detection chamber main body. Detailed Implementation

[0042] To facilitate understanding of this utility model, a more comprehensive description of it will be provided below, along with preferred embodiments. However, it should be understood that these embodiments are merely for more detailed explanation and should not be construed as limiting the utility model in any way, i.e., not limiting the scope of protection of this utility model.

[0043] Example 1

[0044] like Figure 1 As shown, this embodiment discloses a pollutant concentration detection chamber, including a detection chamber body 6, a detector 2, a temperature control device, a data processing module, and a data display module; the detection chamber includes a sample chamber located inside its body, the sample chamber being a cavity within the detection chamber, and also includes a sample chamber inlet 3 and a sample chamber detection port 4;

[0045] The samples include gaseous or liquid pollutants such as formaldehyde and sulfur dioxide. The sample chamber entrance and the sample chamber detection port are sealed with openable and closable transparent windows. The sample chamber entrance is used to place liquid pollutants. The main body of the detection chamber is also equipped with an air inlet and an air outlet connected to the sample chamber for detecting gaseous pollutants. The air inlet and air outlet are connected to the sample inlet pipeline and the sample outlet pipeline, respectively. A flow meter is installed on the sample inlet pipeline. This product is for real-time monitoring of sample concentration. The monitoring process is always dynamic. The sample chamber is used to temporarily store gaseous or liquid samples for a short period of time. After the monitoring reaction is completed, the samples are immediately discharged from the outlet.

[0046] Furthermore, the main body of the detection chamber is a hollow square shell structure, and the sample chamber entrance and sample chamber detection port are respectively located on different sides of the shell to avoid mutual interference.

[0047] A trigger 1 is installed at the sample chamber entrance 3 to input a light signal and trigger a fluorescent reaction between formaldehyde and the reaction solution. A detector 2 is installed at the sample chamber detection port 4 to detect the fluorescent signal emitted by the sample and convert it into an electrical signal. A temperature control device is connected to the detection chamber to monitor and control the temperature of the sample chamber and the detector in real time, ensuring that the reaction takes place under optimal temperature conditions and eliminating the influence of temperature on the measurement results. The electrical signal converted by the detector is analyzed by the data processing module and then transmitted to the data display module to realize real-time monitoring and display of formaldehyde concentration.

[0048] Preferably, there are multiple detectors 2, symmetrically distributed around the sample chamber detection port, and the detection end of the detector extends into the sample chamber. Further, the detectors 2 are fixed to the main body of the detection chamber by a detachable connector. In some embodiments, the detachable connector is cylindrical, with an opening at its center that communicates with the sample chamber detection port 4. The shape and size of the opening are preferably perfectly matched to the sample chamber detection port. The connector is also provided with a connection hole corresponding to the installation position and number of detectors 2, and the detection end of the detector extends into the sample chamber through the connection hole.

[0049] The detachable connector can be connected to the outer wall of the testing chamber body through existing technologies such as threaded connections;

[0050] The testing chamber should be compatible with different types of triggers, such as light-emitting diodes, laser diodes, LEDs, ultraviolet light-emitting diodes, zinc lamps, etc.

[0051] The detection chamber should be compatible with different types of detectors, such as photodiodes, avalanche photodiodes, photomultiplier tubes, and optocouplers.

[0052] The main body of the testing chamber is made of high-quality 5052 aluminum alloy and a blackening manufacturing process to ensure that it can work stably in various environments and has good durability.

[0053] Example 2

[0054] In this embodiment, formaldehyde is detected using the Hantzsch fluorescence method, and the detection chamber is configured as follows:

[0055] Trigger 1 uses an LED lamp with a center wavelength of 410nm, which matches the excitation spectrum peak of the DDL fluorescent material;

[0056] Detector 2 uses a photomultiplier tube to detect 510nm yellow fluorescence;

[0057] The temperature control device includes a temperature sensor that monitors the temperature of the sample chamber and detector in real time;

[0058] The heating / cooling module adjusts the temperature based on feedback from a temperature sensor.

[0059] The control circuit is used to maintain a constant temperature environment of 60-80℃ for formaldehyde detection or 50℃±5℃ for sulfur dioxide detection.

[0060] The specific steps of this embodiment are as follows:

[0061] S1. Input the gaseous or liquid formaldehyde sample to be tested into the sample chamber, turn on the trigger, and use a 410nm LED lamp as the light source to illuminate the sample; at the same time, the temperature control device controls the sample temperature within the optimal reaction temperature range of 60-80℃.

[0062] S2. Formaldehyde in the sample reacts with Hantzsch reaction solution in an acetic acid-ammonium acetate buffer system. 1 mol of formaldehyde reacts with 2 mol of acetylacetone to form the cyclized product 3,5-diacetyl-1,4-dihydrodimethylpyridine (DDL). The reaction equation is as follows:

[0063]

[0064] DDL is a fluorescent substance whose excitation spectrum typically exhibits a main peak in the ultraviolet region, with a maximum peak wavelength of 414 nm and a symmetrical single-peak spectral shape. Its emission spectrum, at an excitation wavelength of 410 nm, can emit 510 nm yellow fluorescence. Curves 2, 3, and 4 in the figure below represent the fluorescence intensity emission spectra of different concentrations of DDL.

[0065] Figure 2 and Figure 3 The effects of reaction temperature and reaction time on the fluorescence intensity of formaldehyde at different concentrations were investigated. It can be seen that the reaction rate increases with increasing temperature. The fluorescence intensity of the reaction system reaches its maximum and remains stable at 60–80℃. At the same temperature, the fluorescence intensity first increases and then remains constant with increasing reaction time. Therefore, the reaction needs to be carried out at 60–80℃ for more than 35 minutes. The optimal reaction pH is 6, and the pH value should be controlled within the range of 5.5–6.5.

[0066] DDL is a fluorescent substance whose excitation spectrum typically exhibits a main peak in the ultraviolet region, with a maximum peak wavelength of 414 nm and a symmetrical single-peak spectral shape. Its emission spectrum, at an excitation wavelength of 410 nm, can emit a 510 nm yellow fluorescence.

[0067] Figure 4 Curves 2, 3, and 4 in the figure represent the fluorescence intensity emission spectra of DDL at different concentrations. Plotting formaldehyde concentration on the x-axis and corresponding fluorescence intensity on the y-axis, the relationship curve within the measurable range is y = 0.0902x + 0.8825. The correlation coefficient R0 shown in the figure is... 2 =0.9995. Within this range, absorbance is directly proportional to formaldehyde content. The higher the absorbance, the higher the formaldehyde content. This can be used to measure formaldehyde content.

[0068] Figure 6The curve showing the relationship between formaldehyde content and DDL absorbance is plotted, with formaldehyde content on the x-axis and the corresponding DDL absorbance on the y-axis. The standard working curve is Y = 0.0035X + 0.00362; the coefficient of determination for linearity of this system is 0.9994. In actual testing, the measurement of low-concentration formaldehyde often produces large errors. The data processing module uses weighted least squares to assign higher weights to low-concentration data and linearize them, thereby correcting for errors and improving the accuracy and reliability of the measurement.

[0069] S3. The detector detects the fluorescence signal emitted by DDL. The photomultiplier tube continuously measures the fluorescence signal emitted by the sample chamber and converts it into an electrical signal. The current signal collected is transposed and amplified by the OPA129 amplifier circuit. Then, the NIUSB-6009 data acquisition card collects the data and transmits it to the computer data processing module through the USB interface. The data processing module uses the weighted least squares method to linearize and correct the low concentration data, and finally obtains the formaldehyde concentration value, which is displayed on the data display module.

[0070] This invention allows for the addition of a temperature control module to the detector to achieve constant temperature in the detection system, reduce measurement errors, and ensure the accuracy of the results. When changing to different types of detectors and triggers, the parameters need to be adjusted and adapted according to the reaction conditions of the analyte, the required measurement accuracy, and the measurement method.

[0071] Example 3

[0072] In this embodiment, ultraviolet fluorescence method is used to detect sulfur dioxide. The configuration of the detection chamber is modified from that in Example 2 as follows:

[0073] The trigger is a 214nm zinc lamp; the detector is equipped with a 230nm filter.

[0074] The specific steps of this embodiment are as follows:

[0075] S1. Ambient air containing gaseous sulfur dioxide passes through the sample inlet line at a constant flow rate. Then, the gaseous sulfur dioxide first passes through a hydrocarbon remover to eliminate the influence of aromatic hydrocarbons in the sample air on the sulfur dioxide measurement results. Then, it passes through a particulate filter to remove interfering particulate matter in the sample, resulting in purified and filtered sample air. The sample air enters the sample chamber at a constant flow rate through a peristaltic pump tube.

[0076] S2. A zinc lamp is used as the source of ultraviolet light, and a 214nm filter is used to filter the ultraviolet light to produce 214nm ultraviolet light. After the purified and filtered sample air enters the sample chamber, the gaseous sulfur dioxide molecules in it will become excited after being irradiated by ultraviolet light with a wavelength of 200-220nm (the 214nm ultraviolet light generated by the zinc lamp and 214nm filter meets the wavelength range requirement). During the process of returning to the ground state, they will emit fluorescence with a wavelength of 240-420nm.

[0077] S3. Signal Detection and Conversion: The generated fluorescence signal passes through a 230nm filter at a 90° angle to the ultraviolet light, is measured by a photomultiplier tube, and converted into an electrical signal. The acquired current signal is transposed and amplified by an OPA129 amplifier circuit, then acquired by an NIUSB-6009 data acquisition card, and transmitted to a computer via a USB interface. The data is then sent to the data processing module. Upon receiving the signal, the data processing module analyzes the linear relationship between fluorescence intensity and sulfur dioxide concentration (e.g., ...). Figure 8 As shown, there is a positive linear correlation between the voltage signal and the sulfur dioxide concentration. The concentration of sulfur dioxide in the sample is calculated. Since the measurement of low concentration sulfur dioxide often produces large errors in actual detection, the data processing module adopts the weighted least squares method to give higher weight to the low concentration data and linearize it to correct it, thereby improving the accuracy and reliability of the measurement. Finally, the concentration value of sulfur dioxide is obtained and displayed on the data display module, thus realizing the online monitoring of sulfur dioxide.

[0078] The measurement accuracy of this device is affected by temperature; as the gas temperature increases, the measured data value gradually decreases. Figure 9 , 10 The graph showing the effect of reaction temperature on measurement error reveals that the error value reaches its lowest point near 50℃, indicating that the fluorescence efficiency of sulfur dioxide gas is highest and the measurement result is closest to the true value at a temperature of 50℃±5℃. Therefore, this device needs to be excited in an environment of 50℃±5℃ to ensure measurement accuracy.

[0079] It should be noted that the above description is a further detailed explanation of the present invention in conjunction with specific embodiments, and should not be construed as limiting the specific implementation of the present invention to these descriptions; the dimensional data in this embodiment do not limit the technical solution, but merely illustrate one specific working condition. For those skilled in the art to which this invention pertains, several simple improvements and modifications can be made without departing from the concept of the present invention, and all such improvements and modifications should be considered to fall within the scope of protection of the present invention.

Claims

1. A pollutant concentration detection chamber, characterized in that, include: The main body of the testing laboratory contains a sample room for storing pollutant samples; The sample chamber entrance and sample chamber testing port are located on different sides of the main body of the testing chamber, and are enclosed by openable and closable windows. The air inlet and outlet are connected to the sample chamber for the detection of gaseous pollutants. The air inlet is connected to the sample inlet line with a flow meter. The trigger, installed at the sample chamber entrance, is used to input light signals into the sample chamber; The detector is installed at the sample chamber detection port and runs through the main body of the detection chamber. It is used to detect the sample fluorescence signal and convert it into an electrical signal. A temperature control device is connected to the main body of the detection chamber and is used to regulate the temperature inside the sample chamber; The data processing module is used to analyze the electrical signals converted by the detector and transmit the analysis results to the data display module in data form; The data display module is used to display pollutant concentrations in real time.

2. The pollutant concentration detection chamber according to claim 1, characterized in that, The detectors are multiple in number and symmetrically distributed around the detection port of the sample chamber, and the detection end of the detector extends into the sample chamber through a detachable connector.

3. The pollutant concentration detection chamber according to claim 2, characterized in that, The detachable connector is cylindrical with an opening in the center that communicates with the sample chamber detection port, and connection holes on the side wall that match the number and position of the detectors, and is detachably connected to the outer wall of the detection chamber body.

4. The pollutant concentration detection chamber according to claim 1, characterized in that, The trigger is selected from light-emitting diodes, laser diodes, LEDs, ultraviolet light-emitting diodes, or zinc lamps; and / or, the detector is selected from photodiodes, avalanche photodiodes, photomultiplier tubes, or optocouplers.

5. The pollutant concentration detection chamber according to claim 1, characterized in that, The temperature control device includes: Temperature sensor to monitor the temperature of the sample chamber and the contaminant samples inside in real time; The control circuit receives the temperature sensor signal and calculates the deviation value, and outputs the control command to the heating / cooling module to maintain a constant temperature environment for pollutant detection. The heating / cooling module adjusts the sample chamber temperature according to the instructions of the control circuit.

6. The pollutant concentration detection chamber according to claim 1, characterized in that, The pollutant samples were formaldehyde or sulfur dioxide.

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