Condenser COD (Chemical Oxygen Demand) titration device

Abstract

The utility model belongs to the field of analytical instruments, and particularly relates to a concatemer COD (Chemical Oxygen Demand) titration device. Comprising a sample disc, more than two placing holes are distributed on the sample disc, and sample cups are clamped in the placing holes; each detection unit comprises a light source capable of emitting detection light to the sample cup and a color sensor used for receiving the detection light, and a detection area capable of containing the sample cup is formed between the light source and the color sensor. By arranging a plurality of groups of detection units, the requirements of COD batch titration and parallel titration are met; by adjusting the angle of the color sensor and the position of the light source, the device can adapt to sample discs with various placement hole layouts and different shapes. The device is simple in structure, high in flexibility, convenient to install and replace, and beneficial to popularization and application in production practice.

Description

Technical Field

[0001] The utility model belongs to the field of analytical instruments, and in particular relates to a multi-unit COD titration device. Background Art

[0002] Chemical oxygen demand is an important indicator of the degree of water pollution, and is also an important parameter in the fields of environmental testing and wastewater treatment. At present, most laboratories heat and digest the samples and then use manual titration to calculate the results. Manual titration can only titrate one sample at a time, and batch titration is not possible, resulting in low test efficiency and high work intensity. In recent years, automated analytical equipment has gradually emerged, improving the efficiency of analysis and testing, but most automated equipment can only titrate one sample at a time and cannot perform batch titration. In order to solve the above problems, it is necessary to develop a batch multi-unit COD titration device to further improve the titration efficiency of automated equipment.

[0003] Existing automated titration equipment typically consists of a dosing unit and a detection unit. A light source and sensor are located below the dosing unit. The light source emits light toward the sample bottle to be tested, while the color sensor receives light reflected or scattered from the titration bottle to detect color. Automated titration equipment reduces labor costs and prevents human factors from affecting titration results.

[0004] However, existing automatic titration equipment can only titrate one test sample at a time. First, this results in low efficiency and cannot meet the requirements of batch titration. Second, when titrating multiple parallel samples, if the interval is too long, it is easy for the redox reaction to continue in the subsequent sample. In addition, the overall heat dissipation of the automatic titration device, especially the heat generated by the light source, may affect the reaction in the untested sample, resulting in biased results and affecting the parallel effect. Finally, in many current automatic titration devices, the color sensor and light source are located on the same side of the test sample. The color sensor receives the reflected light of the sample for analysis, which is easily affected by the reflected light of other internal components, requiring a more complex color analysis algorithm. Utility Model Content

[0005] The utility model aims to overcome the defects of COD titration devices in the prior art, such as low titration efficiency and easy interference of other factors in parallel titration, and provides a multi-unit COD titration device to overcome the above defects.

[0006] In order to achieve the above-mentioned purpose of the invention, the present invention is implemented through the following technical solutions:

[0007] A multi-unit COD titration device, comprising:

[0008] A sample tray, wherein the sample tray has two or more placement holes, and the sample cups are clamped in the placement holes;

[0009] In the present invention, at least two detection units are required, including a light source capable of emitting detection light to the sample cup, and a color sensor for receiving the detection light, wherein a detection area capable of accommodating the sample cup is formed between the light source and the color sensor.

[0010] Existing methods for determining chemical oxygen demand (COD) include the permanganate method and the potassium dichromate method, both of which have established corresponding national standards. The current national standard for the permanganate index is "GB11892-1989 Water Quality - Determination of the Permanganate Index," and the current national standard for the potassium dichromate method is "HJ828-2017 Water Quality - Determination of Chemical Oxygen Demand - Dichromate Method." The endpoint of a COD titration typically relies on the color change of the indicator, but sometimes the color change is not obvious, making it difficult to accurately determine the endpoint. For example, in the potassium dichromate method, the experimenter must determine the endpoint when the solution changes color from yellow to blue-green to reddish-brown, which is prone to errors due to human factors.

[0011] Most existing automatic COD titration instruments can only measure one sample at a time, making them difficult to meet the needs of batch and parallel measurements. If multiple detection units are required to achieve batch titration, the color sensor should ideally detect transmitted light. If the color sensor detects reflected light, the reflected light from multiple light sources will enter the color sensor, causing interference between the multiple measurement units and affecting titration accuracy.

[0012] The utility model includes a sample tray with multiple placement holes, in which sample cups are clamped; it also includes multiple groups of detection units, each detection unit including a group of light sources and color sensors. The sample to be measured is placed in the sample cup and placed in the detection area between the light source and the color sensor. The light source emits detection light of different wavelengths, which passes through the sample and enters the color sensor. The color sensor outputs the result by detecting the changes in the light of different wavelengths.

[0013] Preferably, the color sensor is perpendicular to the line connecting the light source and the detection area. The light receiving surface of the color sensor is usually very small, so when the titration device is automatically running, it is necessary to always ensure that the color sensor is perpendicular to the transmitted light to achieve the best detection effect.

[0014] Preferably, the sample tray is rectangular, the placement holes are evenly arranged on the sample tray, and the placement holes have the same diameter. The rectangular sample tray can accommodate more samples and is suitable for analysis or processing requiring a large number of samples.

[0015] Preferably, the sample tray is circular, the placement holes are evenly arranged on the sample tray, and the placement holes have the same diameter. The circular sample tray is easy to rotate and can better meet the needs of automated titration.

[0016] As a further preferred embodiment, the titration device further comprises a fixing base perpendicular to the radius of the sample tray, and the color sensor is fixed vertically on the fixing base. When the titration device is provided with multiple detection units, all color sensors are fixed on the same fixing base to facilitate circuit layout and data transmission.

[0017] As a further preferred embodiment, the placement holes are arranged in an inner circle and an outer circle, and the placement holes in the inner and outer circles are staggered. During the COD titration process, the measured sample needs to be heated and digested. To facilitate the subsequent titration and digestion process, the diameter of the digestion cup used is usually larger. Therefore, if the digestion cup is used directly for titration, the placement holes should also be correspondingly larger. By staggering the inner and outer circles of the placement holes, the area of the sample tray can be maximized, avoiding the tray being too large and affecting the overall structure.

[0018] Further preferably, the color sensor is rotatably connected to the mounting base, thereby enabling adjustment of the angle between the color sensor and the mounting base. To ensure that the color sensor receives the maximum amount of detection light transmitted through the sample cup, the color sensor should be perpendicular to the transmitted light. Therefore, the color sensor is rotatably connected to the mounting base, allowing for angle adjustment to accommodate different sample cup placement positions within the well.

[0019] As a further preference, the angle is limited to between 45° and 90°.

[0020] Preferably, the titration apparatus further comprises a magnetic stirring device, the magnetic stirring device comprising a magnet placed at the bottom of the sample cup and a magnetic stirrer arranged below the detection area. In the titration process of COD, continuous stirring can accelerate the rate of the chemical reaction, helping to reach the titration endpoint faster. In the titration process, if no stirring is performed, the titrant may form a layer on the surface of the solution, resulting in insufficient contact between the titrant and the titrated solution, affecting the accuracy of the reaction.

[0021] As a further preferred feature, the mounting base covers the detection area, and the light source is vertically fixed to the mounting base. Covering the detection area allows the mounting base to connect the light source and color sensor of the same detection unit. This not only facilitates circuit connection, but also prevents splashing reagents from entering the magnetic stirrer and shortening its life. Furthermore, by disassembling and repositioning the light source, it can be moved left and right relative to the color sensor, allowing the titration device to accommodate both circular and rectangular sample trays.

[0022] Therefore, the utility model has the following beneficial effects:

[0023] (1) The utility model meets the needs of COD batch titration and parallel titration by setting up multiple groups of detection units;

[0024] (2) The present invention adjusts the angle and position of the color sensor and the light source through the preferred solution, which can not only adapt to sample trays with various placement hole layouts, but also can be applied to sample trays of different shapes;

[0025] (2) The utility model has a relatively simple structure, strong flexibility, and is easy to install and replace, which is conducive to its promotion and application in production practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 This is a top view of a multi-unit COD titration device shown in Example 1 of the present utility model;

[0027] Figure 2 This is a top view of a multi-unit COD titration device shown in Example 2 of the present utility model;

[0028] Figure 3 This is a top view of a sample tray of a multi-unit COD titration device shown in Example 2 of the present utility model;

[0029] Figure 4 This is a schematic structural diagram of a multi-unit COD titration device of the present invention;

[0030] In the figure: sample tray 1; placement hole 2; sample cup 3; fixing base 4; detection unit 10; light source 11; color sensor 12; detection area 13; angle α; magnetic stirring device 20; magnet 21; magnetic stirrer 22. DETAILED DESCRIPTION

[0031] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments. Based on these descriptions, a person skilled in the art will be able to implement the present invention. Furthermore, the embodiments of the present invention described below generally represent only a portion of the present invention, rather than all of the embodiments. Therefore, all other embodiments derived by a person skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

[0032] Example 1

[0033] like Figure 1 、 Figure 4 As shown, the multi-unit COD titration device in this embodiment is provided with two detection units 10, which are placed vertically, wherein the light source 11 and the color sensor 12 are located on the same straight line, and the color sensor 12 is fixed on the fixing seat 4 and cannot rotate; a magnetic stirrer 22 is provided under the detection area 13 of each detection unit 10; the sample tray 1 used is rectangular, and is provided with placement holes 2 of the same size and evenly arranged, and a magnet 21 is placed in each sample cup 3.

[0034] The usage process of this embodiment is as follows:

[0035] Move the rectangular sample tray 1 to the designated position, allowing the two sets of test samples to be moved into the two detection areas 13. Activate the magnetic stirrer 22, driving the magnet 21 to simultaneously stir the reagents in the two sample cups 3. Turn on the light source 11 of the detection unit 10, emitting light of a specific wavelength through the sample cups 3, where it is detected by the corresponding color sensor 12. The two sets of samples are titrated simultaneously. When the titration reaches the endpoint, a color change occurs in the sample cups 3. The color sensor 12 detects this color change and outputs a signal to terminate the titration. Repeat the above steps for the next set of samples.

[0036] Example 2

[0037] like Figure 2-4 As shown, the sample tray 1 used in this embodiment is circular, and is provided with placement holes 2 of the same size and arranged evenly. The placement holes 2 are divided into two circles, inner and outer. The placement holes 2 of the inner and outer circles intersect with each other. The placement holes can accommodate the digestion cups used in the COD determination digestion process, and are used directly as sample cups 3 for titration, omitting the step of transferring samples. A magnetic particle 21 is placed in each sample cup 3. The multi-unit COD titration device of this embodiment is provided with two detection units 10, which are arranged vertically, corresponding to the placement holes of the inner and outer circles respectively. The color sensor 12 and the light source 11 are both mounted on a fixed base 4 perpendicular to the radius of the circular sample tray 1, and the fixed base 4 can cover the detection area 13. The color sensor 12 is rotatably connected to the fixed base 4, and the angle α between the color sensor 12 and the fixed base 4 can be adjusted. The light source 11 is detachably arranged on the fixed base 4, so that the light source 11 can move left and right relative to the color sensor 12. By adjusting the angle α and the position of the light source 11 , the staggered placement holes 2 in the inner and outer circles can be adapted so that when the circular sample disk 1 rotates, each group of inner and outer circle sample cups 3 can be moved to the corresponding detection area 13 .

[0038] The usage process of this embodiment is as follows:

[0039] Rotate the circular sample tray 1, moving the outer sample cups 3 containing the sample to be tested into the detection area 13. The inner sample cups containing the sample to be tested are now located in the other detection area. Activate the magnetic stirrer 22, driving the magnet 21 to simultaneously stir the reagents in both sample cups 3. Turn on the detection unit's light source 11, emitting light of a specific wavelength through the sample cups 3, where it is detected by the corresponding color sensor 12. The two sets of samples are titrated simultaneously. When the titration reaches the endpoint, a color change occurs in the sample cups 3. The color sensor 12 detects this color change and outputs a signal to terminate the titration. Repeat the above steps for the next set of samples.

Claims

1. A multi-unit COD titration device, characterized in that: It comprises a sample tray (1), wherein the sample tray (1) is provided with two or more placement holes (2), and a sample cup (3) is clamped in each of the placement holes (2); The invention also includes two or more detection units (10), wherein the detection unit (10) includes a light source (11) capable of emitting detection light to the sample cup (3), and a color sensor (12) for receiving the detection light, and a detection area (13) capable of accommodating the sample cup (3) is formed between the light source (11) and the color sensor (12).

2. A multi-unit COD titration device according to claim 1, characterized in that: The color sensor (12) is perpendicular to a line connecting the light source (11) and the detection area (13).

3. A multi-unit COD titration device according to claim 2, characterized in that: The sample plate (1) is rectangular, the placement holes (2) are evenly arranged on the sample plate (1), and the placement holes (2) have the same diameter.

4. A multi-unit COD titration device according to claim 2, characterized in that: The sample plate (1) is circular, the placement holes (2) are evenly arranged on the sample plate (1), and the placement holes (2) have the same diameter.

5. A multi-unit COD titration device according to claim 4, characterized in that: The titration device further comprises a fixing seat (4) perpendicular to the radius of the sample plate (1), and the color sensor (12) is fixed vertically on the fixing seat (4).

6. A multi-unit COD titration device according to claim 5, characterized in that: The placement holes (2) are divided into an inner circle and an outer circle and are distributed and arranged, and the placement holes (2) of the inner circle and the outer circle are arranged in an interlaced manner.

7. A multi-unit COD titration device according to claim 6, characterized in that: The color sensor (12) is rotatably connected to the fixing seat (4), thereby adjusting the angle (α) between the color sensor (12) and the fixing seat (4).

8. A multi-unit COD titration device according to claim 7, characterized in that: The angle (α) is limited to between 45° and 90°.

9. A multi-unit COD titration device according to claim 8, characterized in that: The titration device further comprises a magnetic stirring device (20), wherein the magnetic stirring device (20) comprises a magnet (21) placed at the bottom of the sample cup (3), and a magnetic stirrer (22) arranged below the detection area (13).

10. A multi-unit COD titration device according to claim 9, characterized in that: The fixing seat (4) covers the detection area (13), and the light source (11) is detachably arranged on the fixing seat (4).

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