A self-calibration titration device and method
By setting a superhydrophobic self-repair anti-corrosion coating on the inner wall of the titration probe of the titration device and using a self-calibration method, the low accuracy, corrosion and icing of the titration device are solved, and the titration accuracy is improved and the instrument self-calibration is achieved, and the use is extended. life.
Patent Information
- Application Number
- CN202211400896.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2022-11-09
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2042-11-09
AI Technical Summary
Existing titration devices are susceptible to temperature, have low titration accuracy, metal probes are prone to corrosion, and cannot be automatically calibrated, resulting in low drop hanging phenomenon and detection accuracy, and titration is prone to icing and blockage in winter.
The ultra-hydrophobic self-repair anti-corrosion coating is installed on the inner wall of the titration probe, and a self-calibration method is used to establish a nonlinear compensation table through experimental presets and online use stages, using the titration time and volume relationships to achieve titration accuracy improvement and instrument self-calibration.
It effectively improves the titration accuracy and detection accuracy, extends the service life of the instrument, realizes maintenance-free and remote self-calibration of the titration device, prevents drip hanging and corrosion, maintains the consistent titration temperature, and avoids blockage of the titration device.
Smart Images
Figure CN115728442B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of titration analysis, and in particular to a self-calibration titration device and method. Background Art
[0002] Titration is a chemical experimental operation and also a means of quantitative analysis. It determines the content of a certain solute through the quantitative reaction of two solutions. It is widely used in food, drug testing, disease control, inspection, commercial inspection, water treatment, petroleum, chemical industry, ocean, electricity, environmental protection, new energy, teaching, scientific research and other fields.
[0003] Technical problems existing in the prior art: (1) Manual titration is performed using a glass burette, which is divided into an acid burette and an alkaline burette, which is not conducive to online detection and is easily affected by thermal expansion and contraction. The titration volume will change and the titration accuracy is low. (2) The metal titration probe is easily corroded by acids and alkalis during titration, which in turn affects the service life of the titration instrument and cannot be automatically calibrated. (3) The existing titration device has a hanging drop phenomenon. For example, the original accuracy is 0.01mL, but due to the hanging drop, it will be 0.05mL during titration, resulting in low accuracy of the instrument's ion content detection. (4) The titration device is prone to ice during titration in winter, causing the titration device to be blocked. Summary of the invention
[0004] The purpose of the present invention is to provide a self-calibration titration device, which solves the problem of hanging drops and corrosion of the titration device by setting a super-hydrophobic self-repairing anti-corrosion coating on the inner wall of the titration probe; and can perform self-calibration of the titration device. The self-calibration method of the present invention can effectively improve the titration accuracy and instrument detection accuracy in a complex titration environment, and at the same time realize maintenance-free and remote self-calibration of the titration instrument.
[0005] To achieve the above object, the present invention adopts the following technical solutions:
[0006] A self-calibration method for a self-calibration titration device, comprising an experiment preset stage and an online use stage;
[0007] The experimental pre-setting stage includes the following steps:
[0008] S1. Select a titrant, set the pulse I of the metering pump, titrate n times, record the time interval of n-1 times, and calculate the average value t of the time interval of n-1 times; weigh the total mass m of the n drops of titrant dripped out by the titration n times, obtain the density ρ of the titrant by a densitometer, and calculate the volume V=m / ρ of the n drops of titrant;
[0009] S2, setting a plurality of different pulses of the metering pump, repeating step S1 under each pulse, and obtaining t and V corresponding to each pulse;
[0010] S3. According to each pulse and its corresponding t and V, the ItV fitting equation of the titrant is obtained by linear fitting method:
[0011] V = A·t + B Equation 1
[0012] V=K·I+bEquation 2
[0013] A, B, K, and b are used as a nonlinear compensation table of the titration solution;
[0014] The online use phase includes the following steps:
[0015] S1', according to equation 2, set the pulse corresponding to the required titration accuracy of the metering pump, titrate n drops of titration liquid, record the time interval of n-1 times, and calculate the average value tc of the n-1 time intervals;
[0016] S2', substitute tc into equation 1, and get the titration volume Vc=A·tc+B;
[0017] S3', calculate the self-calibration coefficient δ = |Vc-V| / V, compare δ with the preset value σ,
[0018] If δ≤σ, the nonlinear compensation table is not updated;
[0019] If δ>σ, then substitute Vc into equation 2 to obtain b'=Vc-K·I, and replace b in the nonlinear compensation table with b' to update the nonlinear compensation table.
[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: utilizing the relationship between titration time and titration volume, first obtaining a nonlinear compensation table of the titration solution through an experimental preset stage; in the online use stage, utilizing the nonlinear compensation table, recalibrating the pulse of the metering drive mechanism according to the titration time, which can effectively improve the titration accuracy and instrument detection accuracy in a complex titration environment, while realizing maintenance-free and remote self-calibration of the titration instrument.
[0021] Another technical solution of the present invention is that in S1 and S1', the temperature of the titration solution is kept consistent.
[0022] The technical solution of the present invention also has that σ=2%.
[0023] The present invention also provides a self-calibration titration device, comprising a titration probe, a metering pump, a metering drive device, a controller, and a photoelectric timer; the metering pump is connected to the titration probe through a pipeline, and the metering drive device is used to set the pulse of the metering pump; the controller comprises a processor and a memory, the memory stores a computer program that can be run on the processor, and when the processor executes the program, S1'~S3' in the self-calibration method of the self-calibration titration device is implemented; the photoelectric timer is connected to the controller, and the photoelectric timer is used to record the time interval between two adjacent drops of titration liquid dripped by the titration probe, and transmit it to the controller.
[0024] The technical solution of the present invention is that the inner wall of the titration probe is provided with a super-hydrophobic self-repairing anti-corrosion coating. By providing a super-hydrophobic self-repairing anti-corrosion coating on the inner wall of the titration probe, the problem of hanging drops and the corrosion problem of the titration probe are solved. On the one hand, the surface super-hydrophobic layer structure can effectively reduce the contact area between the titration solution and the metal surface of the titration probe, reducing the hanging drops phenomenon. On the other hand, the self-repairing characteristics of the corrosion layer can be used to suppress the corrosion of the scratches on the titration probe, prevent the corrosive solution from invading the coating, and increase the service life of the titration probe.
[0025] The technical solution of the present invention is that the super hydrophobic self-repairing anti-corrosion coating adopts SMP-BTA / ATP composite material and is arranged on the inner wall of the titration probe through layer-by-layer self-assembly.
[0026] The technical solution of the present invention also includes a temperature sensor, which is connected to the controller and is used to obtain the temperature of the liquid in the titration probe and transmit it to the controller.
[0027] The technical solution of the present invention also has a heater provided on the titration probe, and the heater is connected to the controller. The heater can be used to heat the titration solution when the ambient temperature is low, so that the titration temperature meets the titration requirements and prevents the titration probe from being frozen and blocked. BRIEF DESCRIPTION OF THE DRAWINGS
[0028] Figure 1 It is a structural schematic diagram of the self-calibration titration device in the present invention;
[0029] Among them: 1-titration probe, 2-metering pump, 3-metering drive device, 4-photoelectric timer, 5-controller, 6-temperature sensor, 7-heater. DETAILED DESCRIPTION
[0030] The present invention will be further described below in conjunction with the accompanying drawings:
[0031] Example 1
[0032] Figure 1 Embodiment 1 of the present invention is shown.
[0033] like Figure 1 As shown, a self-calibration titration device includes a titration probe 1, a metering pump 2, a metering drive device 3, a controller, a photoelectric timer 4, a temperature sensor 6, and a heater 7.
[0034] The controller includes a processor and a memory, wherein the memory stores a computer program that can be run on the processor. When the processor executes the program, S1' to S3' in the self-calibration method of the self-calibration titration device are implemented.
[0035] The metering drive device 3 , the photoelectric timer 4 , the temperature sensor 6 , and the heater 7 are all connected to the controller 5 .
[0036] The metering pump 2 is connected to the titration probe 1 through a pipeline, and the metering drive device 3 is used to set the pulse of the metering pump 2 .
[0037] The photoelectric timer 4 is used to record the time interval between two adjacent drops of titration liquid dropped by the titration probe 1 and transmit the time interval to the controller 5 .
[0038] The temperature sensor 6 is used to obtain the temperature of the liquid in the titration probe 1 and transmit it to the controller 5 .
[0039] The heater 7 is installed on the titration probe 1 and is used to heat the titration solution when the ambient temperature is low, so that the titration temperature meets the titration requirements and prevents the titration probe 1 from being frozen and blocked.
[0040] The titration probe 1 is made of metal, and the inner wall of the titration probe 1 is provided with a super-hydrophobic self-repairing anti-corrosion coating, which is made of SMP-BTA / ATP composite material and is arranged on the inner wall of the titration probe 1 through layer-by-layer self-assembly. By arranging a super-hydrophobic self-repairing anti-corrosion coating on the inner wall of the titration probe 1, the problem of hanging drops and the corrosion problem of the titration device are solved. On the one hand, the surface super-hydrophobic layer structure can effectively reduce the contact area between the titration solution and the metal surface of the titration probe 1, reducing the hanging drops phenomenon. On the other hand, the self-repairing characteristics of the corrosion layer can be used to suppress the corrosion of the scratches of the titration probe 1, prevent the corrosive solution from invading the coating, and improve the service life of the titration probe 1.
[0041] This embodiment also provides a self-calibration method for the self-calibration titration device, including an experiment preset stage and an online use stage;
[0042] The experimental pre-setting stage includes the following steps:
[0043] S1. At 20°C, a titration solution is selected. In this embodiment, a chrome black T solution is selected. The pulse I=98 of the metering pump 2 is set by the metering drive device 3, and the titration is performed five times. The four time intervals of 1.55s, 1.43s, 1.32s, and 1.44s are recorded by the photoelectric timer 4, and the average value t=1.435s of the four time intervals is calculated; the total mass m=m1+m2+m3+m4+m5=0.0617g of the five drops of chrome black T solution dripped out by the five titrations is weighed; the density ρ=1.226 of the chrome black T solution is obtained by a densimeter, and the volume V=m / ρ=0.0617 / 1.226=0.05ml of the five drops of chrome black T solution is calculated, and the titration accuracy at this time is 0.01ml, i.e., the average volume of the chrome black T solution titrated five times.
[0044] S2. Set a plurality of different pulses 200, 300, ... of the metering pump 2 through the metering drive device 3, repeat step S1 under each pulse, and obtain t and V corresponding to each pulse.
[0045] S3, according to each pulse and its corresponding t and V, the ItV fitting equation of chrome black T solution is obtained by linear fitting method:
[0046] V = A·t + B Equation 1
[0047] V=K·I+bEquation 2
[0048] In this embodiment,
[0049] V = 0.18939·t-0.22519 Equation 1
[0050] V = 5.323·10-4·I-0.00238 Equation 2
[0051] That is, A=0.18939, B=-0.22519, K=5.323·10-4, b=-0.00238;
[0052] Using A, B, K, and b as the nonlinear compensation table of the chrome black T solution;
[0053] The online use phase includes the following steps:
[0054] S1', titrate the chrome black T solution at 20°C. According to equation 2, set the pulse I=98 corresponding to the metering pump 2 at an accuracy of 0.01ml through the metering drive device 3, titrate five drops of titrant, record four intervals of 1.66s, 1.57s, 1.62s, and 1.49s through the photoelectric timer 4, and calculate the average of the four time intervals; tc=1.585s.
[0055] S2', substitute tc into equation 1, and get the titration volume Vc=0.18939·1.585-0.22519=0.075mL;
[0056] S3', calculate the self-calibration coefficient δ = |Vc-V| / V = |0.075-0.05| / 0.05*100% = 5.00%, compare δ with the preset value σ,
[0057] If δ≤σ, the nonlinear compensation table is not updated. At this time, the pulse corresponding to the accuracy of 0.01ml is 98;
[0058] If δ>σ, substitute Vc into equation 2 and obtain b'=Vc-K·I=0.075-5.323×10-4×98=0.02283. Replace b=-0.00238 in the nonlinear compensation table with b'=0.02283 and update the nonlinear compensation table. At this time, the pulse I corresponding to the accuracy of 0.01ml is I=(Vb) / K=(0.05-0.02283) / 5.323*10-4=51.04.
[0059] The embodiments described above are merely descriptions of preferred implementation modes of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the protection scope determined by the claims of the present invention.
Claims
1. A self-calibration method for a self-calibration titration device, comprising an experimental preset stage and an online use stage; The experimental pre-setting stage includes the following steps: S1, select a titrant, set the pulse I of the metering pump (2), titrate n times, record the time interval of n-1 times, and calculate the average value t of the time interval of n-1 times; weigh the total mass m of n drops of titrant dripped out by the titration n times, obtain the density ρ of the titrant by a densitometer, and calculate the volume V=m / ρ of the n drops of titrant; S2, setting a plurality of different pulses of the metering pump (2), repeating step S1 under each pulse, and obtaining t and V corresponding to each pulse; S3. According to each pulse and its corresponding t and V, the ItV fitting equation of the titrant is obtained by linear fitting method: V = A·t + B Equation 1 V=K·I+bEquation 2 A, B, K, and b are used as a nonlinear compensation table of the titration solution; The online use phase includes the following steps: S1', according to equation 2, set the pulse corresponding to the required titration accuracy of the metering pump (2), titrate n drops of titration liquid, record the time interval of n-1 times, and calculate the average value tc of the n-1 time intervals; S2', substitute tc into equation 1, and get the titration volume Vc=A·tc+B; S3', calculate the self-calibration coefficient δ = |Vc-V| / V, compare δ with the preset value σ, If δ≤σ, the nonlinear compensation table is not updated; If δ>σ, then substitute Vc into equation 2 to obtain b'=Vc-K·I, and replace b in the nonlinear compensation table with b' to update the nonlinear compensation table.
2. The self-calibration method according to claim 1, characterized in that: In S1 and S1', the temperature of the titrant remains constant.
3. The self-calibration method according to claim 1, characterized in that: σ=2%.
4. A self-calibration titration device, comprising a titration probe (1), a metering pump (2), and a metering drive device (3), wherein the metering pump (2) is connected to the titration probe (1) via a pipeline, and the metering drive device (3) is used to set the pulse of the metering pump (2), characterized in that: The device also comprises a controller and a photoelectric timer (4), wherein the controller comprises a processor and a memory, wherein the memory stores a computer program that can be run on the processor, and when the processor executes the program, steps S1' to S3' in the self-calibration method of the self-calibration titration device according to any one of claims 1 to 3 are implemented; the photoelectric timer (4) is connected to the controller (5), and the photoelectric timer (4) is used to record the time interval between two adjacent drops of titration liquid dropped by the titration probe (1), and transmit the time interval to the controller (5).
5. The self-calibration titration device according to claim 4, characterized in that: The inner wall of the titration probe (1) is provided with a super-hydrophobic self-repairing anti-corrosion coating.
6. The self-calibration titration device according to claim 5, characterized in that: The super hydrophobic self-repairing anti-corrosion coating adopts a SMP-BTA / ATP composite material and is arranged on the inner wall of the titration probe (1) through layer-by-layer self-assembly.
7. The self-calibration titration device according to claim 4, characterized in that: It also includes a temperature sensor (6), which is connected to the controller (5) and is used to obtain the temperature of the liquid in the titration probe (1) and transmit it to the controller (5).
8. The self-calibration titration device according to claim 4, characterized in that: The titration probe (1) is provided with a heater (7), and the heater (7) is connected to the controller (5).