PH value testing device
By using nitrogen purging and a magnetic stirrer in the pH testing device, pH testing is ensured to be performed in an oxygen-free environment, thus solving the error problem caused by carbon dioxide absorption by the solution and improving the accuracy and repeatability of the test.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU YONGMAI RECYCLING TECH CO LTD
- Filing Date
- 2025-05-16
- Publication Date
- 2026-04-24
AI Technical Summary
During pH testing, prolonged exposure of the solution to air leads to the absorption of carbon dioxide, causing a decrease in pH value. This is especially noticeable when the solution approaches neutrality, resulting in significant errors and affecting the repeatability and accuracy of the test.
A pH testing device is used, which is connected to high-purity nitrogen through gas inlet and outlet pipelines. Nitrogen gas is used to replace the air in the test cup. Combined with a magnetic stirrer and a metering pump, the test is ensured to be carried out in an oxygen-free environment. A pH electrode and a sealing ring are used to ensure airtightness. The metering pump adds carbon dioxide-free solvent for dilution and mixing.
It significantly improves the accuracy and repeatability of pH value detection, and is particularly suitable for organic solvent systems that are sensitive to carbon dioxide, reducing detection errors.
Smart Images
Figure CN224163609U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a pH value testing device, belonging to the field of pH detection technology. Background Technology
[0002] In the field of pH measurement, especially for the detection of some organic solvents, such as N-methylpyrrolidone (NMP), several technical challenges are often encountered during the testing process. Because the organic solvent and water are mixed in the solution system, the electrode stabilization time is relatively long during detection, typically requiring several minutes to obtain the result. During this period, if the solution is exposed to air for an extended period, it will absorb carbon dioxide (CO2), causing the pH value of the solution to decrease and thus introducing detection errors. Moreover, the more carbon dioxide the solution absorbs, the larger the detection error becomes, especially when the pH value of the solution is close to neutral, where this error is more pronounced, severely affecting the repeatability and accuracy of pH detection. Therefore, existing pH measurement methods and techniques have significant shortcomings when handling such carbon dioxide-sensitive samples, necessitating a detection device and method that can effectively avoid carbon dioxide interference to improve the accuracy and reliability of detection. Utility Model Content
[0003] The purpose of this invention is to overcome the shortcomings of the existing technology and provide a pH value testing device to solve the problem of pH value decrease and detection error caused by the solution being exposed to air for a long time and absorbing CO2 during detection. In particular, when the solution pH value is close to neutral, the more CO2 absorbed, the greater the error, resulting in very poor repeatability of pH detection.
[0004] To solve the above-mentioned technical problems, this utility model is implemented using the following technical solution:
[0005] On one hand, this utility model provides a pH testing device, including a testing cup, a pH meter, and a magnetic assembly. A gas inlet pipe, a gas outlet pipe, and a solvent pipe are respectively connected to both sides of the testing cup. The testing cup is connected to a gas inlet / outlet assembly via the gas inlet and gas outlet pipes. The gas inlet / outlet assembly includes a pressure reducing valve and high-purity nitrogen. The gas inlet pipe is connected to the high-purity nitrogen via the pressure reducing valve.
[0006] The test cup is provided with a pH electrode socket, a sample inlet, and a solvent line hole. The pH meter is inserted into the test cup through the pH electrode socket. The sample inlet is used to add the sample to be tested. One end of the solvent line is inserted into the test cup through the solvent line hole, and the other end is connected to a metering pump.
[0007] The magnetic assembly includes a magnetic stirrer located outside the test cup and a rotor placed inside the test cup. The magnetic stirrer drives the rotor to rotate through magnetic coupling, so that the sample to be tested is uniformly mixed.
[0008] Preferably, the gas inlet pipeline is connected to the nitrogen source for the high-purity nitrogen supply and is discharged through the gas outlet pipeline.
[0009] Preferably, the gas inlet pipeline and the gas outlet pipeline are respectively equipped with an inlet valve and an outlet valve for adjusting the nitrogen inflow rate and velocity.
[0010] Preferably, the pH electrode socket is equipped with a matching pH electrode sealing ring.
[0011] Preferably, the pH meter includes a pH electrode, which can be configured with different types of electrodes.
[0012] Preferably, the bottom of the detection cup is provided with a discharge pipe, and a discharge valve for controlling the discharge of waste liquid is installed on the discharge pipe.
[0013] Preferably, the inlet port is used to add the sample to be tested, and the type of sample to be tested includes solid samples and liquid samples.
[0014] Preferably, the metering pump is equipped with decarbonated water or a corresponding solvent to quantitatively dilute the sample to be tested added through the injection port.
[0015] Preferably, the volume of the CO2-removing water or corresponding solvent is 5 ml to 100 ml.
[0016] Preferably, the testing cup has a volume of 50ml-200ml and is made of a transparent and corrosion-resistant material.
[0017] Compared with the prior art, the beneficial effects achieved by this utility model are as follows:
[0018] The detection cup of this invention is connected to a nitrogen source via a gas inlet pipe and has a gas outlet pipe. The nitrogen atmosphere is adjusted by controlling the inlet and outlet valves to eliminate interference from internal air and carbon dioxide. The top of the detection cup has a pH electrode socket equipped with a sealing ring to ensure airtightness. The pH meter extends into the cup through this socket for measurement. It also has a sample inlet and a sealing plug to support the injection of solid or liquid samples into an oxygen-free environment. A quantitative pump accurately delivers a predetermined volume of decarbonated water or solvent into the detection cup through a solvent pipe hole. Combined with a magnetic component to drive the rotor inside the cup to rotate, it achieves rapid and uniform mixing of the sample and solvent. After the test is completed, the pressure of high-purity nitrogen drives the waste liquid to be discharged through the bottom pipe, and the cleaning solution is injected by the quantitative pump to complete the automatic cleaning. The entire device operates in a closed environment, effectively isolating external carbon dioxide interference and significantly improving the repeatability and accuracy of pH value detection. It is especially suitable for the analysis of organic solvent systems or samples sensitive to trace amounts of carbon dioxide. Attached Figure Description
[0019] Figure 1 This is a schematic diagram of a pH value testing device provided in an embodiment of the present invention;
[0020] In the diagram: 1. Detection cup; 2. pH meter; 21. pH electrode; 22. Electrode sealing ring; 3. Gas inlet pipe; 31. Inlet valve; 4. Gas outlet pipe; 41. Outlet valve; 5. Magnetic stirrer; 6. Pressure reducing valve; 7. Sample inlet; 8. Solvent pipe; 9. Metering pump; 10. High-purity nitrogen; 11. Rotor; 12. Magnetic assembly; 13. Discharge pipe; 131. Drain valve; 14. Gas inlet / outlet assembly. Detailed Implementation
[0021] The present invention will be further described below with reference to the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and should not be used to limit the scope of protection of the present invention.
[0022] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.
[0023] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances. Example 1
[0024] This utility model introduces a pH value testing device, including a testing cup 1, a pH meter 2, and a magnetic component 12. The testing cup 1 serves as the core container of the entire device, with a gas inlet pipe 3, a gas outlet pipe 4, and a solvent pipe 8 connected to its two sides, respectively. The testing cup 1 is connected to a gas inlet / outlet component 14 via the gas inlet pipe 3 and the gas outlet pipe 4. The gas inlet / outlet component 14 includes a pressure reducing valve 6 and high-purity nitrogen 10. The gas inlet pipe is connected to the high-purity nitrogen 10 via the pressure reducing valve. The pressure reducing valve 6 is used to regulate the input pressure of nitrogen in the high-purity nitrogen 10, thereby injecting nitrogen into the testing cup 1 and venting air.
[0025] The test cup 1 is also equipped with multiple functional ports, namely a pH electrode socket, a sample inlet 7, and a solvent line hole. The pH electrode socket is used to install the pH meter 2, which is inserted into the test cup 1 through the pH electrode socket to ensure the accuracy of the test. The sample inlet 7 is used to add the sample to be tested and is equipped with a sealing plug, which can not only facilitate the addition of the sample but also ensure the sealing of the device. The solvent line 8 is a channel for delivering carbon dioxide water (CO2) or the corresponding solvent. One end of it is inserted into the test cup 1 through the solvent line hole, and the other end is connected to the metering pump 9.
[0026] The magnetic assembly 12 includes a magnetic stirrer 10 located outside the test cup 1 and a rotor 11 placed inside the test cup 1. The magnetic stirrer 10 drives the rotor 11 to rotate through magnetic coupling, so that the sample to be tested can be mixed evenly.
[0027] In a further embodiment of this utility model, the gas inlet pipe 3 and the gas outlet pipe 4 are used to connect to and discharge the nitrogen source in the high-purity nitrogen 10, and are respectively equipped with an inlet valve 31 and an outlet valve 41 to regulate the nitrogen inflow and flow rate, thereby providing a stable nitrogen atmosphere for the device during the detection process. By introducing nitrogen into the detection cup 1, carbon dioxide in the air is replaced, preventing carbon dioxide from dissolving in the sample and affecting the accuracy of the pH value.
[0028] In a further embodiment of this utility model, the pH meter 2 includes a pH electrode, and the pH electrode socket is equipped with a matching pH electrode sealing ring 22. The pH electrode socket not only facilitates the installation of different types of pH electrodes, such as the METTLERTOLEDO Science Pro-ISM, but also ensures the sealing of the inside of the detection cup 1, preventing carbon dioxide in the outside air from entering the detection environment.
[0029] In a further embodiment of this utility model, the injection port 7 is used to add the sample to be tested. The sample to be tested can be a solid sample or a liquid sample, and is equipped with a sealing plug. Under the premise of ensuring sealing, a volume of 5ml-100ml of deCO2 water or a corresponding solvent is added in conjunction with the quantitative pump 9, thereby quantitatively diluting the sample to be tested added through the injection port 7 to meet different testing needs.
[0030] To accommodate samples of different volumes, the entire test cup has a volume of 50ml - 200ml and is made of transparent, corrosion-resistant material.
[0031] In addition, the bottom of the test cup 1 is provided with a discharge pipe 13, which is equipped with a drain valve 131 for controlling the discharge of waste liquid, so that the waste liquid can be discharged in time by using the pressure of nitrogen after the test is completed, so as to prepare for the next test.
[0032] In summary, this device effectively prevents interference from carbon dioxide, improves the accuracy and repeatability of pH value detection, and is especially suitable for samples sensitive to carbon dioxide and detection scenarios with stringent pH requirements. Example 2
[0033] The pH testing device based on Example 1 performs the following measurement process:
[0034] 1. Prepare the testing equipment:
[0035] Ensure that the test cup 1 is clean and dry, then insert the pH meter 2 of the corresponding model into the pH electrode socket of the test cup 1, and ensure the seal by using the configured pH electrode sealing ring 22;
[0036] Ensure that the gas inlet pipe 3 and the gas outlet pipe 4 are properly connected, and install the inlet valve 31 and the outlet valve 41 to regulate the nitrogen inflow and flow rate respectively;
[0037] Check that metering pump 9 is working properly and prepare CO2 water or the appropriate solvent.
[0038] 2. Eliminate air from the test cup:
[0039] Close the drain valve 131 on the drain pipe 13 at the bottom of the test cup 1, and open the inlet valve 31 and the outlet valve 41;
[0040] A nitrogen source is provided by high-purity nitrogen 10. After the nitrogen input pressure is adjusted by the pressure regulating valve 6, a stable flow of nitrogen is introduced into the detection cup 1 through the gas inlet pipe 3 to remove air from the detection cup 1 and prevent carbon dioxide dissolution from interfering with subsequent detection.
[0041] 3. Add decarbonated water or a suitable solvent.
[0042] Start the metering pump 9 and add a certain volume (5ml-100ml) of deCO2 water or corresponding solvent into the test cup 1 through the solvent pipeline hole 8;
[0043] Turn on the magnetic stirrer 10, and drive the rotor 11 inside the detection cup 1 to rotate through magnetic coupling, so that the solvent is mixed evenly.
[0044] 4. Add the sample to be tested:
[0045] Add the sample (solid or liquid) to be tested into the test cup 1 through the injection port 7, and immediately seal the injection port 7 with the sealing plug to ensure airtightness.
[0046] 5. Sample mixing:
[0047] Continue stirring with magnetic stirrer 10 to ensure that the sample to be tested is thoroughly mixed with decarbonated water or the corresponding solvent, and that the sample is completely dissolved or thoroughly mixed.
[0048] 6. pH value measurement:
[0049] After the sample and solvent are thoroughly mixed or completely dissolved, turn on the pH meter to measure the pH value. During the measurement, maintain a nitrogen atmosphere to prevent carbon dioxide from entering the test cup and affecting the measurement results.
[0050] 7. Waste liquid disposal:
[0051] After the measurement is completed, turn off the magnetic stirrer 10, open the drain valve 131, close the outlet valve 41, and use nitrogen pressure to discharge the waste liquid through the drain pipe 13 to the test cup 1.
[0052] 8. Clean the test cup:
[0053] After the waste liquid is drained, close the inlet valve 31, restart the metering pump 9, and add a certain volume of de-CO2 water or a suitable solvent to the detection cup 1 to clean the detection cup 1. After cleaning, repeat the waste liquid draining step (step 7) to drain the cleaned waste liquid.
[0054] 9. Electrode maintenance:
[0055] After cleaning, remove pH electrode 2 from the detection cup 1 and immerse the electrode in a maintenance solution to extend its service life.
[0056] In summary, if multiple measurements are required, steps 1-9 above can be repeated. Between each measurement, ensure that the test cup 1 and pH electrode 2 are thoroughly cleaned and replaced with fresh de-CO2 water or solvent to avoid sample cross-contamination and measurement errors.
[0057] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present utility model, and these improvements and modifications should also be considered within the protection scope of the present utility model.
Claims
1. A pH value testing device, characterized in that, The device includes a test cup (1), a pH meter (2), and a magnetic assembly (12). The test cup (1) is connected to a gas inlet pipe (3), a gas outlet pipe (4), and a solvent pipe (8) on both sides. The test cup (1) is connected to a gas inlet / outlet assembly (14) through the gas inlet pipe (3) and the gas outlet pipe (4). The gas inlet / outlet assembly (14) includes a pressure reducing valve (6) and high-purity nitrogen (10). The gas inlet pipe (4) is connected to the high-purity nitrogen (10) through the pressure reducing valve (6). The test cup (1) is provided with a pH electrode socket, a sample inlet (7) and a solvent line hole. The pH meter (2) is inserted into the test cup (1) through the pH electrode socket. The sample inlet (7) is used to add the sample to be tested and is equipped with a sealing plug. One end of the solvent line (8) is inserted into the test cup (1) through the solvent line hole, and the other end is connected to the metering pump (9). The magnetic assembly includes a magnetic stirrer (5) located outside the test cup (1) and a rotor (11) placed inside the test cup (1). The magnetic stirrer (5) drives the rotor (11) to rotate through magnetic coupling, so that the sample to be tested is uniformly mixed.
2. The pH testing device according to claim 1, characterized in that, The gas inlet pipe (3) is connected to the nitrogen source transported by the high-purity nitrogen (10) and discharged through the gas outlet pipe (4).
3. The pH testing device according to claim 2, characterized in that, The gas inlet pipeline (3) and the gas outlet pipeline (4) are respectively equipped with an inlet valve (31) and an outlet valve (41) for adjusting the flow rate and velocity of nitrogen.
4. The pH testing device according to claim 1, characterized in that, The pH electrode socket is equipped with a matching pH electrode sealing ring (22).
5. The pH testing device according to claim 1, characterized in that, The pH meter (2) includes a pH electrode (21), which can be configured with different types of electrodes.
6. The pH testing device according to claim 1, characterized in that, The bottom of the test cup (1) is provided with a discharge pipe (13), and a discharge valve (131) for controlling the discharge of waste liquid is installed on the discharge pipe (13).
7. The pH testing device according to claim 1, characterized in that, The inlet (7) is used to add the sample to be tested, and the types of the sample to be tested include solid samples and liquid samples.
8. The pH testing device according to claim 7, characterized in that, The metering pump (9) is equipped with decarbonated water or a corresponding solvent to quantitatively dilute the sample to be tested added through the injection port (7).
9. The pH testing device according to claim 8, characterized in that, The volume of the decarbonated water or corresponding solvent is 5ml-100ml.
10. The pH testing device according to claim 1, characterized in that, The test cup (1) has a volume of 50ml-200ml and is made of transparent and corrosion-resistant material.