CN110146575A - Temperature, Concentration Testing and automatic control device based on three electrode chemical systems - Google Patents
Temperature, Concentration Testing and automatic control device based on three electrode chemical systems Download PDFInfo
- Publication number
- CN110146575A CN110146575A CN201910511495.7A CN201910511495A CN110146575A CN 110146575 A CN110146575 A CN 110146575A CN 201910511495 A CN201910511495 A CN 201910511495A CN 110146575 A CN110146575 A CN 110146575A
- Authority
- CN
- China
- Prior art keywords
- temperature
- electrode
- concentration
- electrically connected
- ion concentration
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/4163—Systems checking the operation of, or calibrating, the measuring apparatus
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
- G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
- G01N27/26—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating electrochemical variables; by using electrolysis or electrophoresis
- G01N27/416—Systems
- G01N27/48—Systems using polarography, i.e. measuring changes in current under a slowly-varying voltage
Abstract
The invention discloses temperature, Concentration Testing and automatic control devices based on three electrode chemical systems, it include: power supply and the three-electrode system detection device connected to power supply respectively, constant potential drive module, digital analog converter, signal conditioning module, analog-digital converter, processor, temperature sensor, power driving device, temperature-adjusting device, concentration adjusting device and display control unit, in which: permanent electric power driving module is electrically connected with three-electrode system detection device and digital analog converter respectively；Signal conditioning module is electrically connected with three-electrode system detection device and analog-digital converter respectively；Analog-digital converter is electrically connected with processor and temperature sensor respectively；Processor is electrically connected with display control unit and power driving device respectively；Power driving device is electrically connected with temperature-adjusting device and concentration adjusting device respectively.The accurate quickly measurement in real time to Chlorine in Solution ion concentration is realized, and is able to achieve the closed-loop control of solution temperature, Chlorine in Solution ion concentration.
Description
Technical field
The present invention relates to do Concentration Detection field, and in particular to temperature, concentration inspection based on three electrode chemical systems
Survey and automatic control device.
Background technique
Chloride ion is a kind of ion component very common in water, and chlorine ion concentration is one very heavy in Water quality measurement
The index wanted, chlorine ion concentration are also chemical research, biomedical, critically important one of the parameter in the fields such as construction material, experiment
The method of room measurement chlorine ion concentration mainly has: test paper method, ion titration, the chromatography of ions, spectrophotometry, Atomic absorption
Method, electrochemical process, wherein test paper method is without quantitative analysis, and ion titration is cumbersome, and error is big, and pollution is big, ion chromatography
The detecting instrument of method is huge, expensive, and spectrophotometry pollution is big, measurement cost is high, atomic absorption method to solution coloration and
Turbidity requires high, measurement cost height, and the electro-chemical measuring apparatus in laboratory is traditional electrochemical workstation, and electrochemistry
Work station is not suitable for the research of non-traditional electrode, especially electrod-array.
Currently, electrochemical measurement chlorine ion concentration mainly utilizes the electrodes such as ion-selective electrode to constitute three-electrode electro Chemical
Measurement system is completed to measure, the country for three electrode test systematic researches still in the laboratory simulations stage, and mostly
In terms of several research concentrates on the production of electrode.Solution temperature to be measured is an important factor for influencing final measurement, in the prior art
Chlorine ion concentration measuring instrument can only realize and measure at a constant temperature that measurement result can generate mistake because solution temperature changes
Difference.
Therefore the invention discloses temperature, Concentration Testing and automatic control devices based on three electrode chemical systems, realize
Accurate quickly measurement in real time to Chlorine in Solution ion concentration, and it is able to achieve solution temperature, Chlorine in Solution ion concentration
Closed-loop control.
Summary of the invention
In view of the above shortcomings of the prior art, the invention discloses temperature, concentration based on three electrode chemical systems
Detection and automatic control device realize the accurate quickly measurement in real time to Chlorine in Solution ion concentration, and are able to achieve solution
The closed-loop control of temperature, Chlorine in Solution ion concentration.
In order to solve the above technical problems, present invention employs the following technical solutions:
Temperature, Concentration Testing and automatic control device based on three electrode chemical systems, comprising: power supply and respectively with power supply
The three-electrode system detection device of connection, constant potential drive module, digital analog converter, signal conditioning module, analog-digital converter, place
Manage device, temperature sensor, power driving device, temperature-adjusting device, concentration adjusting device and display control unit, in which:
Permanent electric power driving module is electrically connected with three-electrode system detection device and digital analog converter respectively；
Signal conditioning module is electrically connected with three-electrode system detection device and analog-digital converter respectively；
Analog-digital converter is electrically connected with processor and temperature sensor respectively；
Processor is electrically connected with display control unit and power driving device respectively；
Power driving device is electrically connected with temperature-adjusting device and concentration adjusting device respectively.
Preferably, three-electrode system detection device includes working electrode, reference electrode and auxiliary electrode, working electrode, ginseng
It is ion-selective electrode than electrode and auxiliary electrode.
Preferably, include the following steps: when measuring ion concentration
Practical chlorine ion concentration in Chloride Solution to be measured is measured using chronoamperometry；
Chlorine ion concentration after temperature-compensating is compensated is carried out to practical chlorine ion concentration using temperature-compensation method.
Preferably, it is described using temperature-compensation method to practical chlorine ion concentration carry out temperature-compensating compensated after chlorine from
In sub- concentration:
Based on formulaTemperature benefit is carried out to practical chlorine ion concentration
It repays；
In formula:RsmFor the boundary of ion selective membrane and detected solution composition
The equivalent resistance in face, RmFor the equivalent resistance of ion selectivity membrane interface, n is electron transfer number, and F is Faraday constant, EHTo apply
Add detection voltage on the working electrode (s, R is ideal gas constant, and K is constant, and T is solution absolute temperature, and I is when stablizing
The response current of electrode, pClTTo there is chlorine ion concentration when temperature-compensating.
Preferably, temperature-adjusting device includes the electrically heated rod and semiconductor refrigerating being electrically connected respectively with power driving device
Piece.
Preferably, concentration adjusting device include be electrically connected respectively with power driving device Chloride Solution input water pump and
Pure water inputs water pump, and the Chloride Solution concentration that Chloride Solution inputs water pump input is greater than the dense of Chloride Solution to be measured
Degree.
The invention discloses temperature, Concentration Testing and automatic control devices based on three electrode chemical systems, comprising: power supply
And connect to power supply respectively three-electrode system detection device, constant potential drive module, digital analog converter, signal conditioning module,
Analog-digital converter, processor, temperature sensor, power driving device, temperature-adjusting device, concentration adjusting device and display control
Device, in which: permanent electric power driving module is electrically connected with three-electrode system detection device and digital analog converter respectively；Signal condition mould
Block is electrically connected with three-electrode system detection device and analog-digital converter respectively；Analog-digital converter respectively with processor and temperature sensing
Device electrical connection；Processor is electrically connected with display control unit and power driving device respectively；Power driving device respectively with temperature
Regulating device and concentration adjusting device electrical connection.The accurate quickly measurement in real time to Chlorine in Solution ion concentration is realized, and
It is able to achieve the closed-loop control of solution temperature, Chlorine in Solution ion concentration.
Detailed description of the invention
In order to keep the purposes, technical schemes and advantages of invention clearer, the present invention is made into one below in conjunction with attached drawing
The detailed description of step, in which:
Fig. 1 is the knot of the temperature disclosed by the invention based on three electrode chemical systems, Concentration Testing and automatic control device
Structure schematic diagram；
Fig. 2 is equivalent circuit diagram of the ion-selective electrode in detected solution；
Fig. 3 is to calculate voltage signal and its corresponding current graph according to Nernst equation；
Fig. 4 is PID controller block diagram；
Fig. 5 is global procedures block diagram；
Fig. 6 is actual measurement hygrogram of the set temperature than room temperature when high；
Fig. 7 is actual measurement hygrogram of the set temperature than room temperature when low；
Fig. 8 is the measurement concentration map of lower setting concentration；
Fig. 9 is the measurement concentration of higher setting concentration；
Figure 10 to Figure 14 is a kind of power circuit diagram of specific embodiment of the present invention；
Figure 15 is a kind of microcontroller circuit figure of specific embodiment of the present invention；
Figure 16 is a kind of three-electrode system interface circuit figure of specific embodiment of the present invention；
Figure 17 is a kind of potentiostat circuit figure of specific embodiment of the present invention；
Figure 18 is a kind of signal conditioning circuit figure of specific embodiment of the present invention；
Figure 19 is a kind of analog to digital conversion circuit figure of specific embodiment of the present invention；
Figure 20 is a kind of D/A converting circuit figure of specific embodiment of the present invention；
Figure 21 is a kind of temperature sensor circuit figure of specific embodiment of the present invention；
Figure 22 is a kind of key circuit figure of specific embodiment of the present invention；
Figure 23 is a kind of display screen circuit diagram of specific embodiment of the present invention；
Figure 24 is a kind of debugging download circuit figure of specific embodiment of the present invention；
Figure 25 is a kind of indicator light circuit figure of specific embodiment of the present invention.
Specific embodiment
The present invention is described in further detail with reference to the accompanying drawing.
As shown in Figure 1, the invention discloses temperature, Concentration Testing and automatic control dresses based on three electrode chemical systems
It sets, comprising: power supply and the three-electrode system detection device connected to power supply respectively, constant potential drive module, digital analog converter, letter
Number conditioning module, analog-digital converter, processor, temperature sensor, power driving device, temperature-adjusting device, concentration adjust dress
It sets and display control unit, in which:
Permanent electric power driving module is electrically connected with three-electrode system detection device and digital analog converter respectively；
Signal conditioning module is electrically connected with three-electrode system detection device and analog-digital converter respectively；
Analog-digital converter is electrically connected with processor and temperature sensor respectively；
Processor is electrically connected with display control unit and power driving device respectively；
Power driving device is electrically connected with temperature-adjusting device and concentration adjusting device respectively.
Compared with prior art, the present invention can be by the temperature of temperature sensor measurement solution to be measured, and according to acquisition
Temperature information carries out chlorine ion concentration after temperature-compensating is compensated to the practical chlorine ion concentration measured, avoid because
The measurement error that solution temperature variation occurs.In addition, the invention by solution concentration detection, solution temperature control and it is molten
The control of liquid concentration is combined togather, and can be used as the experimental provision that school and each scientific research institution use.
In conclusion the present invention realizes the accurate quickly measurement in real time to Chlorine in Solution ion concentration, and it is able to achieve
The closed-loop control of solution temperature, Chlorine in Solution ion concentration.
In the prior art, chloride test method has: titration, spectrophotometry, the chromatography of ions, atomic absorption method,
Ion selective electrode method etc. in the present invention, selects ion selective electrode method to carry out measurement of concetration, low with development cost, real
Now simply, the features such as scalability is strong, and measuring speed is fast, and accuracy is higher.
Chlorine ion concentration measurement is that three-electrode electro Chemical measurement body is constituted using electrodes such as ion-selective electrodes in the present invention
System realizes the detection to solution concentration using chronoamperometry, when it is implemented, using high precision digital-to-analog converter and operation
Amplifier constitutes potentiostatic circuit, and carries out current-voltage conversion to the weak current response signal of electrode, while realizing high increasing
Benefit amplification and filtering, measure the voltage after conditioning using high-precision adc, and temperature sensor may be implemented pair
The real-time detection of solution temperature, while temperature-compensating is carried out to chlorine ion concentration testing result by algorithm, improve chloride ion
The accuracy of Concentration Testing result.
In order to accurately measure the potential change on chloride ion working electrode, detection sensitivity is improved, the present invention is using three electricity
The chlorine ion concentration detection method of polar body system chronoamperometry is used according to the relationship of Nernst equation ion concentration and temperature
Temperature-compensating measures the solution concentration under different temperatures, measures the sound in the sodium chloride solution of various concentration by chronoamperometry
Electric current is answered, is demarcated with the sodium chloride solution of normal concentration.
When it is implemented, three-electrode system detection device includes working electrode, reference electrode and auxiliary electrode, work electricity
Pole, reference electrode and auxiliary electrode are ion-selective electrode.
Three-electrode system is electrochemical measurement using more electrochemical sensor, and corresponding three electrodes are work electricity
Pole, reference electrode and auxiliary electrode.
Working electrode (WE): and the electrode of substance generation electrochemical reaction, working electrode, common working electrode has glass
Carbon disk electrode, gold disc electrode, platinum disk electrode and other metal plate-like working electrodes, there are also sheet metal working electrode and
Powdery electrode, modified electrode etc..
Reference electrode (RE): make when being measuring electrode potential referring to the electrode compared.Standard hydrogen electrode is ideal electrode,
It is actually not easy to realize.Therefore we have accurately known when actually carrying out electrode potential measurement using electrode potential
And again sufficiently stable electrode as referring to the electrode compared.
Auxiliary electrode (CE): auxiliary electrode is also named to electrode, is used to through electric current with realization polarization of electrode.Research
When cathodic process, auxiliary electrode makees anode, and when studying anodic process, auxiliary electrode makees cathode.The area of auxiliary electrode is general
Bigger than Electrode, this reduces the current densities on auxiliary electrode, are polarized it not substantially in measurement process, because
And common platinum filament, platinum plate electrode make auxiliary electrode, also can be used kept in research medium inert metal material such as Ag,
Ni, W, Pb etc..
When it is implemented, it can be using the PCL-1 type Chloride selective electrode of Shanghai Lei Ci company as work in the present invention
Make electrode；Using the DJS-1 type platinum conductance electrode of Shanghai Lei Ci company as auxiliary electrode；It is sweet using the double salt bridge saturations of 217 types
Mercury electrode is as reference electrode.
When it is implemented, including the following steps: when measuring ion concentration
Practical chlorine ion concentration in Chloride Solution to be measured is measured using chronoamperometry；
Chlorine ion concentration after temperature-compensating is compensated is carried out to practical chlorine ion concentration using temperature-compensation method.
Ion-selective electrode is a kind of electrochemical sensor that effects of ion activity or concentration are measured using film potential, from
Son selection electrode method is that a kind of current-responsive using ion-selective electrode in detected solution or potential response are specific to measure
The method of ion concentration.
Ion-selective electrode mainly includes three parts:
(1) interface of ion selective membrane and detected solution composition, equivalent capacity Cms, equivalent resistance Rms；
(2) ion selectivity membrane interface, equivalent capacity Cm, equivalent resistance Rm；
(3) interface of ion selective membrane and base material composition, equivalent capacity Csm, equivalent resistance Rsm。
The equivalent circuit of the above three parts is as described in Figure 2.Due to the equivalent resistance R of detected solutionsFar smaller than Rms、RmWith
Rsm, therefore R in the detection processsIt is negligible.
E as shown in Figure 2H3 parts can be divided into, as shown in formula (22):
EH=Esm+Em+Ems (22)
In formula, EHTo apply detection voltage on the working electrode (s, EsmWith EmsRespectively matrix-film potential and film-solution
Phase boundary potential, EmFor film potential.
According to Nernst equation, EmsThere is the relationship of formula (23) with detected solution intermediate ion concentration:
In formula: α is the activity to measured ion in the solution, and K is constant, R is ideal gas constant, T is that solution is absolutely warm
Degree, n are electron transfer number, and F is Faraday constant.In t1In time, Cms、CmAnd CsmCapacitor charging is carried out, when capacitor is full of, electricity
Stream tends towards stability, at this time Esm、EmsAlso tend towards stability value:
Esm=IMRsm (24)
Em=IMRm (25)
Wherein IMResponse current when to stablize.Formula (23)~(25) substitution formula (22) is obtained:
Response current I can be obtained by formula (26)MExpression formula are as follows:
In formula,The negative of chlorine ion concentration is indicated frequently with pCl in formula (27)
Logarithm.That is pCl=-lg α is therefore:
Chronoamperometry is a kind of simple and widely used electrochemical measuring technique.Its working principle is: by outer
Making alive keeps the voltage between working electrode and reference electrode constant, measures the response between working electrode and auxiliary electrode
Electric current calculates the chlorine ion concentration of detected solution according to Nernst equation.The pulse voltage signal of application and its corresponding electricity
Stream is as shown in Figure 3.EHTo detect voltage, EHIt is applied between WE and RE, very high sound will be generated between WE and CE suddenly at this time
Electric current is answered, with t1Chloride ion enters in electrode in detected solution in time, and response current can decline rapidly, when electrode film two
When the chlorine ion concentration of side reaches balance, response current tends towards stability, and generally takes t1Response current I after time terminal stabilizationM,
For calculating solution ion concentration.ELFor set voltage, setting time t2, set voltage expands the chloride ion in electrode again
It is scattered in solution, returns to original state electrode.
When it is implemented, after the use temperature-compensation method obtains compensation to the progress temperature-compensating of practical chlorine ion concentration
In chlorine ion concentration:
Temperature-compensating is carried out to practical chlorine ion concentration based on formula (31)；
By the basic principle of ion selective electrode method it is found that detected solution temperature is one can not ignore in Nernst equation
A variable, experiment discovery temperature have extremely important influence to the result of chloride test, it is necessary to ion selective electrode method
The result of measurement carries out temperature-compensating, just can guarantee the accuracy of final detection result.
In formula:Since g and h are related with temperature, at different temperatures, to electricity
Pole carries out temperature-compensating, improves the precision and stability of chlorine ion electrode.PCl when not temperature compensated known to formula (29)0
Calculation formula:
In formula: T0Kelvin degree (298K) when being 25 DEG C,Pass through formula
(29) pCl when temperature-compensating has been obtainedTCalculation formula:
In formula:According to the above analysis, chronoamperometry setting is measured every time
For 10 periods, preceding 5 period is used for the balance of electrode and detection system；5 periodicity extraction t afterwards1Response electricity when time terminal stabilization
Flow IM, as the response current value for calculating ion concentration to be measured after carrying out averagely.
Temperature is measured using PT100 temperature-sensitive resistor in the present invention, its own resistance and temperature have good line
Sexual intercourse is easy to the processing of data.
When it is implemented, temperature-adjusting device includes the electrically heated rod and semiconductor being electrically connected respectively with power driving device
Cooling piece.
When it is implemented, concentration adjusting device includes the Chloride Solution input water being electrically connected respectively with power driving device
Pump and pure water input water pump, and the Chloride Solution concentration that Chloride Solution inputs water pump input is greater than Chloride Solution to be measured
Concentration.
Engineering in practice, the adjuster control law being most widely used be ratio, integral, differential control, abbreviation PID
Control, also known as PID are adjusted.PID controller appearance has nearly 70 years history so far, it is simple with its structure, stability is good, work
Reliably, one of major technique that is easy to adjust and becoming Industry Control.When the structure and parameter of controlled device cannot be grasped completely,
Or when cannot get accurate mathematical model, when other technologies of control theory are difficult to use, the structure and parameter of system controller
It must be determined by experience and field adjustable, it is at this moment the most convenient using PID control technology.PID appears in simulation control at first
In system processed, traditional analog pid controller is the function that it is realized by hardware (electronic component, pneumatic and Hydraulic Elements)
's.With the appearance of computer, it is transplanted to computer control system, by original hard-wired function software
Instead of to form Digital PID Controller, algorithm is known as Digital PID Algorithm.Digital PID Controller has very strong
Flexibility, can be according to test and experience on-line tuning parameter, therefore available better control performance.Its control block diagram is such as
Shown in Fig. 4.
Wherein:
P:Proportion (ratio) is exactly input deviation multiplied by a constant.
I:Integral (integral) is exactly to carry out integral operation to input deviation.
D:Derivative (differential), differentiates to input deviation.
PID calculation formula is as follows:
In formula: U (t) is the output valve of current PID controller, mistake of the err (t) between t moment actual value and setting value
Difference, derr (t) are the differential of t moment err (t), and k is proportionality coefficient, TIFor integration time constant, TDFor derivative time constant.For
PID is realized on the processors such as computer, it is necessary to above-mentioned formula discretization, in order to the calculating of the processors such as computer.
To realize PID on the processors such as computer, it is necessary to above-mentioned formula discretization, in order to processors such as computers
It calculates.
PID calculation formula after discretization:
In formula: U (k) is the output of kth time sampling PID controller, err (k) be kth time sampling actual value and setting value it
Between error, err (k-1) be kth -1 time sampling actual value and setting value between error, KpFor proportionality coefficient, T is sampling week
Phase.
In the present invention, solution is heated using electrically heated rod, is realized and is freezed using semiconductor chilling plate, according to temperature
The temperature of sensor measurement and the temperature of setting make the difference and are sent into temperature PID control device, export setting heating control according to temperature PID
Device output or refrigeration controler output processed, to realize the purpose of regulating and controlling temperature.
The concentrated solution for being pumped into chloride ion-containing into container using water pump in the present invention or the not side of the pure water of chloride ion-containing
Formula realizes the control of solution chloride ion concentration, and it is poor to be made according to the chlorine ion concentration of the result of chlorine ion concentration measurement and setting, will be poor
It is sent into chlorine ion concentration PID controller, chloride ion-containing should be pumped into according to the output of chlorine ion concentration PID controller judgement
The pure water of concentrated solution or not chloride ion-containing simultaneously controls water pump.
In the present invention, processor can use the microprocessor STM32F103C8T6 based on ARM-Cortex M3 kernel,
It is completed under program using the program of IAR Embedded Workbench IDE exploitation STM32F103C8T6, and on this IDE
It carries and debugging, global procedures block diagram is as shown in Figure 5.
IAR Systems is the supplier of embedded system development tool and service.Company is found in nineteen eighty-three, provides
Product includes: Integrated Development Environment (IDE) with C/C++ compiler and debugger, real time operating system and middleware, exploitation
External member, hardware emulator and state machine modeling tool, IAR Embedded Workbench are that IAR Systems company is micro-
One Integrated Development Environment IAR EW of processor exploitation, supports ARM, AVR, 8051, the chip cores platform such as MSP430.
IAR Embedded Workbench for ARM (referred to as: IAR EWARM) is suitable for the integrated of arm processor
Environment is developed, the main feature of IAR EWARM has: IAR ARM C/C++Compiler, the powerful editor of height optimization
Device, IAR ARM Assembler, project manager, IAR XAR and XLIB build library and IAR DLIB C/C++ Runtime Library etc.
That can be used in the present invention is IAR Embedded Workbench for ARM 8.32.2, integrates open herein
The design of driver of modules and the designs of data processing algorithm such as ADC, DAC, display screen are completed in hair ring border.
Before using the device of the invention, debugged, comprising:
The debugging of three-electrode system detection device:
The principle of chlorine ion concentration is measured it is found that applying one between working electrode and reference electrode according to chronoamperometry
When determining the step signal of size, very high response current will be generated between working electrode and auxiliary electrode, with detected solution
Middle chloride ion enters in electrode, and response current can decline rapidly, when the ion concentration of electrode film two sides reaches balance, response
Electric current tends towards stability, and the concentration of Chlorine in Solution ion can be obtained by the electric current after stabilization.
When applying the step voltage of 0.5V to auxiliary electrode, the electric current of working electrode will appear mutation, then can be not
In time more than 500 milliseconds stablize, starting ADC measurement stablize after voltage, repeatedly measurement after be averaged can be obtained with
The relevant value of chlorine ion concentration in detected solution.
Temperature-adjusting device debugging:
The resistance of PT100 temperature sensor and the relationship of temperature are linear relationship, pass through the programmable current source of ADC chip
The constant current for applying 1mA to PT100, the voltage generated on PT100 are sent into ADC and are measured, such temperature sensor
Temperature and the output valve of ADC are also linear relationship, are measured with the thermometer that precision is 1% with PT100 simultaneously, obtain multiple groups
The value of ADC and the value of thermometer carry out linear fit with Matlab, obtain fitting formula write-in microprocessor, can be by ADC's
Output is converted into temperature.Temperature is compared and analyzed with the temperature that thermometer measures after PT100 is fitted, and the results are shown in Table 1.
1 temperature-measuring module test data of table
Required solution temperature is maintained using PID close loop negative feedback control algolithm, is controlled and is driven according to the output of pid algorithm
Dynamic model block realizes refrigeration or heating, and because temperature control belongs to Control Systems with Time Delays, commonly lag control in Industry Control can be used
Parameter tuning model (Ziegler-Nichols parameter tuning method) processed is as shown in table 2.
2 Ziegler-Nichols of table adjusts model
Wherein:
Kc: only under proportional component control condition, the steady-state error of control system reaches Kp value when minimum as far as possible.
Pc: only under proportional component control condition, the concussion period of control system.
Ti: the time of integration of control system.
Td: the derivative time of control system.
T:PID control sampling calculating cycle.
Kp, Ki, Kd: the parameter adjusted.
It is repeatedly adjusted, 27 DEG C of 45.00 DEG C > room temperature of set temperature, temperature Control PID actual effect is as shown in Figure 6.
27 DEG C of 20.00 DEG C < room temperature of set temperature, temperature Control PID actual effect is as shown in Figure 7.
As it can be seen that temperature controls error within the scope of ± 0.07 DEG C of set temperature, meets and be expected.
Concentration adjusting device debugging:
The value that three-electrode system collects is demarcated repeatedly with the standard chloride ion of various concentration, obtains collection value
With the corresponding relationship of concentration of standard solution, fitting obtains formula and microprocessor is written, while real-time temperature is substituted into formula
Make temperature-compensating, finally obtains the solution chloride ion concentration that three-electrode system is adopted.Again with other three kinds of three-electrode system measurement
Various concentration obtains standard solution to verify the accuracy of testing result, obtains that the results are shown in Table 3.
3 chloride ion measurement module test data of table
Required solution chloride ion concentration is maintained using PID close loop negative feedback control algolithm, according to the output of pid algorithm
It controls drive module and realizes high concentration solution and low concentration solution, the synthermal control of chlorine ion concentration control belongs to Delay control
Common Delay control parameter tuning model (the parameter tuning side Ziegler-Nichols in Industry Control can also be used in system
Method).
It is repeatedly adjusted, setting value 0.5mol/L, concentration Control PID actual effect is as shown in Figure 8.
Setting value is 1.86mol/L, and concentration Control PID actual effect is as shown in Figure 9.
As it can be seen that solution concentration controls error within the scope of the ± 0.05mol/L of setting concentration, meets and be expected.
The following are a kind of circuit diagrams of specific embodiment of the invention:
1 power circuit
Entire circuit system is by battery or source of stable pressure input voltage, since the devices such as amplifier are powered using positive-negative power, because
This needs a power module to generate generating positive and negative voltage.
(1) ± 5V voltage
+ 5V is generated by the LDO chip TL1963 of TI company by input power pressure stabilizing, as shown in Figure 10.
- 5V is generated by the charge pump TPS60403 of TI company from+5V pressure stabilizing, as shown in figure 11.
(2) ± 2.5V voltage, ADC needs ± 2.5V voltage is as analog power
+ 2.5V is obtained by LDO voltage stabilizing chip RT9013 from+5V pressure stabilizing, as shown in figure 12.
- 2.5V is obtained by negative pressure voltage stabilizing chip TPS72301 from -5V pressure stabilizing, as shown in figure 13.
(3) microprocessor needs 3.3V to power, and 3.3V is obtained by LDO voltage stabilizing chip SPX3819 from+5V pressure stabilizing, such as Figure 14
It is shown.
2 microprocessor circuits
Microprocessor controls the operation of whole system, carries out the operation of data and the control of external equipment, and the present apparatus uses
32-bit microprocessor STM32F103C8T6, Flash capacity based on ARM-Cortex M3 kernel is 64KB, and SRAM capacity is
20KB, highest 72MHz working frequency can realize hardware multiplication and hardware division in the monocycle, have timer, ADC, SPI,
The peripheral hardwares such as I2C, DMA, GPIO, PWM, operating voltage 2V-3.6V, operating temperature are -40 DEG C -85 DEG C.Resource and performance are enough, work
Work is stablized, suitable for the microprocessor as this system, as shown in figure 15.
3 three-electrode system interfaces
The method that this system uses the three electrode chloride tests based on chronoamperometry, needs three electrodes to form,
Respectively working electrode WE, reference electrode RE, auxiliary electrode CE.Electrode interface circuit is as shown in figure 16.
4 potentiostat circuits
Potentiostat is electrochemistry, most basic instrument in electroanalysis test.Potentiostat circuit is also many Special electrics
The core of test chemical instrument.In the device of this research, potentiostat is used for the electricity between working electrode and reference electrode
Position control is in a certain fixed current potential.Potentiostat circuit figure is as shown in figure 17.
5 signal conditioning circuits
Under the driving of potentiostat, working electrode can generate response current, which passes through operational amplifier reality
Existing current-voltage is converted and is amplified, then is filtered by second-order active power filter circuit to remove noise, circuit such as Figure 18
It is shown.
6 analog to digital conversion circuits (ADC)
ADC is for the measurement of electrode response voltage and the measurement of temperature, using Texas Instruments (Texas Instrument)
16 high-precision adc parts ADS1120, ADS1120 are integrated with multifrequency nature, are suitable for weak-signal measurement, use
SPI interface, circuit are as shown in figure 19.
7 D/A converting circuits (DAC)
DAC output voltage provides scanning voltage for potentiostat, to realize different constant potentials, using Texas
The high-precision of Instruments (Texas Instrument) company, low-power consumption, 16 digit mode converter part DAC8562 of low noise, the device
It is driven using SPI interface, circuit is as shown in figure 20.
8 temperature sensor circuits
Temperature detection is measured using constant current supply scheme, and sensor uses PT100 platinum resistance thermometer sensor, its resistance value can be with
The variation of temperature and change.100 after PT indicate that its resistance value at 0 DEG C is 100 ohm, and at 100 DEG C, its resistance value is about
It is 138.5 ohm.Constant 1mA electric current is exported by the programmable current source module of ADC, constant 1mA electric current PT100 generates electricity
The AD conversion module that this voltage is sent into ADC is completed conversion, obtains temperature data, circuit is as shown in figure 21 by pressure.
9 key circuits
Using 6 keys, respectively determination, upper and lower, left and right, cancellation, for debugging or inputting parameter, 6 keys
6 IO of microprocessor are respectively connected to, IO is pressed the button using internal pull-up input, and IO is pulled low, and unclamps key, and IO becomes high,
Circuit is as shown in figure 22.
10 display screen circuits
Using 1.3 cun of IPS color LCD screens, 240*240 resolution ratio, 16 RGB565 color formats are gone here and there using 8 SPI
Mouthful, highest is subjected to the clock rate of 65MHz, and circuit is as shown in figure 23.
11 debugging download circuits
Reserved 2 line SWD debugging interfaces reserve AccessPort all the way or extension use, circuit for debugging and downloading program
As shown in figure 24.
12 indicator light circuits
It is used to indicate circuit working state, using RGB three-color LED light, circuit is as shown in figure 25.
Finally, it is stated that the above examples are only used to illustrate the technical scheme of the present invention and are not limiting, although passing through ginseng
According to the preferred embodiment of the present invention, invention has been described, it should be appreciated by those of ordinary skill in the art that can
To make various changes to it in the form and details, without departing from the present invention defined by the appended claims
Spirit and scope.
Claims (6)
1. temperature, Concentration Testing and automatic control device based on three electrode chemical systems characterized by comprising power supply and
Three-electrode system detection device, constant potential drive module, digital analog converter, the signal conditioning module, mould connected to power supply respectively
Number converter, processor, temperature sensor, power driving device, temperature-adjusting device, concentration adjusting device and display control dress
It sets, in which:
Permanent electric power driving module is electrically connected with three-electrode system detection device and digital analog converter respectively；
Signal conditioning module is electrically connected with three-electrode system detection device and analog-digital converter respectively；
Analog-digital converter is electrically connected with processor and temperature sensor respectively；
Processor is electrically connected with display control unit and power driving device respectively；
Power driving device is electrically connected with temperature-adjusting device and concentration adjusting device respectively.
2. temperature, Concentration Testing and automatic control device as described in claim 1 based on three electrode chemical systems, feature
It is, three-electrode system detection device includes working electrode, reference electrode and auxiliary electrode, working electrode, reference electrode and auxiliary
Helping electrode is ion-selective electrode.
3. temperature, Concentration Testing and automatic control device as described in claim 1 based on three electrode chemical systems, feature
It is, includes the following steps: when measuring ion concentration
Practical chlorine ion concentration in Chloride Solution to be measured is measured using chronoamperometry；
Chlorine ion concentration after temperature-compensating is compensated is carried out to practical chlorine ion concentration using temperature-compensation method.
4. temperature, Concentration Testing and automatic control device as claimed in claim 3 based on three electrode chemical systems, feature
It is, described that practical chlorine ion concentration is carried out after temperature-compensating is compensated in chlorine ion concentration using temperature-compensation method:
Based on formulaTemperature-compensating is carried out to practical chlorine ion concentration；
In formula:RsmFor ion selective membrane and detected solution composition interface etc.
Imitate resistance, RmFor the equivalent resistance of ion selectivity membrane interface, n is electron transfer number, and F is Faraday constant, EHTo be applied to work
Make the detection voltage on electrode, R is ideal gas constant, and K is constant, and T is solution absolute temperature, and I is electrode when stablizing
Response current, pClTTo there is chlorine ion concentration when temperature-compensating.
5. temperature, Concentration Testing and automatic control device as described in claim 1 based on three electrode chemical systems, feature
It is, temperature-adjusting device includes the electrically heated rod and semiconductor chilling plate being electrically connected respectively with power driving device.
6. temperature, Concentration Testing and automatic control device as described in claim 1 based on three electrode chemical systems, feature
It is, concentration adjusting device includes the Chloride Solution input water pump being electrically connected respectively with power driving device and pure water input
Water pump, the Chloride Solution concentration that Chloride Solution inputs water pump input are greater than the concentration of Chloride Solution to be measured.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910511495.7A CN110146575B (en) | 2019-06-13 | 2019-06-13 | Temperature and concentration detection and automatic control device based on three-electrode chemical system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201910511495.7A CN110146575B (en) | 2019-06-13 | 2019-06-13 | Temperature and concentration detection and automatic control device based on three-electrode chemical system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN110146575A true CN110146575A (en) | 2019-08-20 |
| CN110146575B CN110146575B (en) | 2020-07-14 |
Family
ID=67591291
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201910511495.7A Expired - Fee Related CN110146575B (en) | 2019-06-13 | 2019-06-13 | Temperature and concentration detection and automatic control device based on three-electrode chemical system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN110146575B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111912945A (en) * | 2020-08-05 | 2020-11-10 | 湖南酃渌酒业有限公司 | White spirit alcohol degree monitoring device and monitoring method |
| CN113970579A (en) * | 2020-07-23 | 2022-01-25 | 中国科学院金属研究所 | Real-time online detection method for deposition rate of chloride ions in air in atmospheric environment |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58198749A (en) * | 1982-05-13 | 1983-11-18 | Masayoshi Hoshina | Apparatus for measuring concentration of electrolyte solution |
| US6238555B1 (en) * | 1997-11-07 | 2001-05-29 | Bioquest | Amperometric halogen control system |
| WO2015132737A1 (en) * | 2014-03-04 | 2015-09-11 | Geolab S.R.L. | System and method for detecting and monitoring chlorine ion concentration and ph in concrete structures |
| CN105738438A (en) * | 2016-02-19 | 2016-07-06 | 中国地质调查局水文地质环境地质调查中心 | Instrument and method for fast detecting bicarbonate radical and carbonate radical in water through double-electrode method |
| CN205826588U (en) * | 2016-06-16 | 2016-12-21 | 广州华清环境监测有限公司 | A kind of Cl ~-Monitoring device |
| CN106525923A (en) * | 2016-10-27 | 2017-03-22 | 中国地质调查局水文地质环境地质调查中心 | Rapid detection system and method for fluoride ions in water |
| CN107543848A (en) * | 2017-06-29 | 2018-01-05 | 深圳市赛亿科技开发有限公司 | A kind of milk objectionable impurities detection means based on electronic tongues |
-
2019
- 2019-06-13 CN CN201910511495.7A patent/CN110146575B/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS58198749A (en) * | 1982-05-13 | 1983-11-18 | Masayoshi Hoshina | Apparatus for measuring concentration of electrolyte solution |
| US6238555B1 (en) * | 1997-11-07 | 2001-05-29 | Bioquest | Amperometric halogen control system |
| WO2015132737A1 (en) * | 2014-03-04 | 2015-09-11 | Geolab S.R.L. | System and method for detecting and monitoring chlorine ion concentration and ph in concrete structures |
| CN105738438A (en) * | 2016-02-19 | 2016-07-06 | 中国地质调查局水文地质环境地质调查中心 | Instrument and method for fast detecting bicarbonate radical and carbonate radical in water through double-electrode method |
| CN205826588U (en) * | 2016-06-16 | 2016-12-21 | 广州华清环境监测有限公司 | A kind of Cl ~-Monitoring device |
| CN106525923A (en) * | 2016-10-27 | 2017-03-22 | 中国地质调查局水文地质环境地质调查中心 | Rapid detection system and method for fluoride ions in water |
| CN107543848A (en) * | 2017-06-29 | 2018-01-05 | 深圳市赛亿科技开发有限公司 | A kind of milk objectionable impurities detection means based on electronic tongues |
Non-Patent Citations (1)
| Title |
|---|
| 陈吉勇: "氯离子浓度检测的研究与实现", 《中国优秀硕士学位论文全文数据库 工程科技I辑》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113970579A (en) * | 2020-07-23 | 2022-01-25 | 中国科学院金属研究所 | Real-time online detection method for deposition rate of chloride ions in air in atmospheric environment |
| CN113970579B (en) * | 2020-07-23 | 2022-10-11 | 中国科学院金属研究所 | Real-time online detection method for deposition rate of chloride ions in air in atmospheric environment |
| CN111912945A (en) * | 2020-08-05 | 2020-11-10 | 湖南酃渌酒业有限公司 | White spirit alcohol degree monitoring device and monitoring method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN110146575B (en) | 2020-07-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Yan et al. | Review of progresses on clinical applications of ion selective electrodes for electrolytic ion tests: from conventional ISEs to graphene-based ISEs | |
| Manjakkal et al. | Screen printed thick film reference electrodes for electrochemical sensing | |
| Srinivasan et al. | An introduction to electrochemical impedance spectroscopy | |
| CN110146575A (en) | Temperature, Concentration Testing and automatic control device based on three electrode chemical systems | |
| CN105738438B (en) | A kind of bipolar electrode method realizes bicarbonate radical and carbonate rapid detection apparatus and its method in water | |
| Criscuolo et al. | All-solid-state ion-selective electrodes: A tutorial for correct practice | |
| Lindner et al. | Switched wall jet for dynamic response measurements | |
| Simpson | Practical techniques for ion-selective electrodes | |
| JPS638423B2 (en) | ||
| CN104569112A (en) | Continuous on-line water ion concentration detection method based on ion selective electrode | |
| Liu et al. | Implementation of a microfluidic conductivity sensor—A potential sweat electrolyte sensing system for dehydration detection | |
| JO'M et al. | Experimental and theoretical examination of methods of obtaining double-layer parameters | |
| Rumpf et al. | Calibration-free measurement of sodium and potassium in undiluted human serum with an electrically symmetric measuring system | |
| CN104034760A (en) | Multifunctional tin plate surface characteristic testing device and use method thereof | |
| CN106525923B (en) | Fluorine ion rapid detection system and its method in water | |
| KR20190113038A (en) | Integrated Electrochemical Analysis Equipment including potentiostat, Electrochemical Impledance Spectroscopy and Electrochemical Quarts Crystal Microbalance | |
| Osteryoung | Developments in electrochemical instrumentation | |
| Barnes et al. | Double potential step chronoamperometry at a microband electrode: Theory and experiment | |
| Matsen et al. | A potentiostat for amperometric kinetic studies | |
| Richter Jr | Automatic Coulometric Titrations Involving Amperometric End Point | |
| Wagner et al. | Handheld measurement device for field-effect sensor structures: Practical evaluation and limitations | |
| Wunderli et al. | Metrological Aspects of Activity Measurements in Mixed Electrolytes by Ion‐Selective Electrodes | |
| Zoltowski | A study of transport of hydrogen in self-stressed metals by a one-port transfer function | |
| Wang et al. | Electrolyte Technologies | |
| JPH1164275A (en) | Oxidation-reduction potential measuring device |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| CB03 | Change of inventor or designer information |
Inventor after: Xiong Han Inventor after: Lu Zexiao Inventor after: Xie Haoran Inventor after: Mou Jingwen Inventor after: Tian Fengchun Inventor before: Xiong Han Inventor before: Lu Zexiao Inventor before: Xiao Haoran Inventor before: Mou Jingwen Inventor before: Tian Fengchun |
|
| CB03 | Change of inventor or designer information | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant | ||
| CF01 | Termination of patent right due to non-payment of annual fee |
Granted publication date: 20200714 |
|
| CF01 | Termination of patent right due to non-payment of annual fee |