Water sample alkalinity measuring device and method
阅读说明：本技术 一种水样碱度测量装置及方法 (Water sample alkalinity measuring device and method ) 是由 吕运昌 陈云龙 边宝丽 于 2021-08-12 设计创作，主要内容包括：本发明涉及一种水样碱度测量装置及方法,装置包括控制器、测量部件和加样部件,测量部件包括水样容器、发射模块和接收模块,通过发射模块和接收模块发出的光线穿过待测水样,测定待测水样的接收电压值,从而通过电压值的变化准确地识别两个滴定终点,自动滴定、测量,完全替代了手工滴定和人工判断终点,符合相关标准和方法,能够实时、准确地测量水质中的酚酞碱度和总碱度；相比于肉眼观察指示剂的变色,确定指示剂的变色范围,本发明的装置和方法避免了不同人员判断终点不同的问题,保证了测量的精准度,适应环境能力强,能够实现在线和实时测量。(The invention relates to a water sample alkalinity measuring device and method, the apparatus includes the controller, measures part and application of sample part, measure the part including container of water sample, emission module and receiving module, the light through emission module and receiving module sends out passes the water sample to be measured, determine the receiving voltage value of the water sample to be measured, thus discern two titration end points accurately through the change of the voltage value, automatic titration, measure, totally substitute and titrate and judge the end point manually, accord with relevant standard and method manually, can measure phenolphthalein alkalinity and total alkalinity in the water quality accurately in real time; compared with the method of observing the color change of the indicator through eyes and determining the color change range of the indicator, the device and the method provided by the invention avoid the problem that different personnel judge different end points, ensure the measurement accuracy, have strong environmental adaptability and can realize online and real-time measurement.)
1. A water sample alkalinity measuring apparatus, comprising:
a controller;
the measuring component comprises a water sample container, an emission module and a receiving module, the water sample container is used for placing a water sample to be measured, the emission module and the receiving module are both electrically connected with the controller, and the emission module and the receiving module are oppositely arranged on two sides of the water sample container;
the sample adding component comprises a first quantitative pump, a second quantitative pump and a third quantitative pump, wherein the first quantitative pump is connected with a standard hydrochloric acid solution container and a water sample container through a pipeline, the second quantitative pump is connected with a phenolphthalein solution container and the water sample container through a pipeline, the third quantitative pump is connected with a methyl orange solution container and the water sample container through a pipeline, and the first quantitative pump, the second quantitative pump and the third quantitative pump are electrically connected with the controller.
2. The device for measuring the alkalinity of a water sample according to claim 1, wherein the controller comprises a main board, an output control board, a signal board, a display screen and a power supply, and the output control board, the signal board, the display screen and the power supply are all electrically connected with the main board; the output control board is electrically connected with the first fixed displacement pump, the second fixed displacement pump and the third fixed displacement pump and is used for controlling the actions of the first fixed displacement pump, the second fixed displacement pump and the third fixed displacement pump; the signal board is electrically connected with the transmitting module and the receiving module and is used for sending signals to the transmitting module and receiving signals to the receiving module.
3. The apparatus for measuring alkalinity of water samples as claimed in claim 2, wherein the measuring unit further comprises a stirrer, the stirrer is installed at the bottom of the water sample container, and the stirrer is electrically connected with the main board through the output control board.
4. The device for measuring the alkalinity of a water sample as claimed in claim 2, wherein the signal board comprises an amplifying circuit, a measuring circuit and a single chip microcomputer which are connected in sequence, the measuring circuit CAN measure an electric signal of the receiving module, the measuring circuit is connected with the main board through an internal CAN bus, and the main board is provided with a resistive touch screen interface and a CAN _ bus communication interface.
5. The device for measuring the alkalinity of a water sample as claimed in any one of claims 1 to 4, wherein the emitting module comprises a light emitting diode light source and a current limiting resistor which are connected in series, the light emitting diode light source can emit parallel light with a fixed wavelength, and the receiving module comprises a photomultiplier tube.
6. A method for measuring alkalinity of a water sample, which is carried out by using the alkalinity measuring device of any one of claims 1 to 4, and comprises the following steps:
step (1), taking a water sample to be tested, placing the water sample into a water sample container, recording the volume of the water sample to be tested as V, and recording the receiving voltage value of the water sample to be tested as a blank voltage value A0；
Adding a phenolphthalein indicator into the water sample to be detected, and recording the receiving voltage value of the water sample to be detected as an initial voltage value A1；
Step (3) judging the initial voltage value A1And the blank voltage value A0If the difference exceeds the preset range, firstly adding a hydrochloric acid solution until the receiving voltage value of the water sample to be detected is the first characteristic receiving voltage value, then adding a methyl orange indicator into the water sample to be detected, and then adding the hydrochloric acid solution again until the receiving voltage value of the water sample to be detected is the first characteristic receiving voltage valueThe receiving voltage value of the water sample to be detected is a second characteristic receiving voltage value, and the volume V of the hydrochloric acid solution added firstly is recorded1Volume V of the hydrochloric acid solution to be added again2And the concentration c of the hydrochloric acid solution1(HCl), otherwise proceeding to step (4);
step (4) adding a methyl orange indicator into the water sample to be detected, then adding a hydrochloric acid solution to the receiving voltage value of the water sample to be detected to the second characteristic receiving voltage value, and recording the volume V of the added hydrochloric acid solution3And the concentration c of the hydrochloric acid solution2(HCl)。
7. The alkalinity measuring method of claim 6, wherein: in the step (2), the initial voltage value A is judged1And the blank voltage value A0Whether the difference value exceeds the preset range is specifically as follows:
if | A0-A1|≤0.2×A0Then, the initial voltage value A is judged1And the blank voltage value A0The difference value of (a) does not exceed a preset range;
if | A0-A1|＞0.2×A0Then, the initial voltage value A is judged1And the blank voltage value A0The difference value of (a) exceeds a preset range;
the preset range is 0.2 xA0。
8. The alkalinity measuring method of claim 6, wherein: the first characteristic receiving voltage value is the blank voltage value A0。
9. The alkalinity measuring method of claim 6, wherein: in the step (3), the calculation method of phenolphthalein alkalinity and total alkalinity in the water sample to be detected comprises the following steps:
JDP＝V1×c1(HCl)×1000/V；
JD＝(V1+V2)×c1(HCl)×1000/V；
the JDPIs phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V1is the volume of the hydrochloric acid solution added first, in milliliters (mL);
V2the volume of hydrochloric acid solution added again is in milliliters (mL);
c1(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
and V is the volume of the water sample to be detected, and the unit is (mL).
10. The alkalinity measuring method of claim 6, wherein: in the step (4), the calculation method of phenolphthalein alkalinity and total alkalinity in the water sample to be detected comprises the following steps:
JDP＝0；
JD＝(0+V3)×c2(HCl)×1000/V；
the JDPIs phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V3the volume of the hydrochloric acid solution added is in milliliters (mL);
c2(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
and V is the volume of the water sample to be detected, and the unit is (mL).
Technical Field
The invention belongs to the technical field of ion content monitoring, and particularly relates to a device and a method for measuring alkalinity of a water sample.
Background
The alkalinity of water refers to the amount of hydrogen ion-accepting substances contained in water, such as hydroxide, carbonate, bicarbonate, phosphate, hydrogen phosphate, silicate, hydrogen silicate, sulfite, humate, ammonia, and the like, which are common alkaline substances in water and which react with acids. The alkalinity is an important index for industrial boilers/industrial circulating cooling equipment, and the addition amount of sodium carbonate and other substances needs to be controlled according to the alkalinity, so that the water components of the boiler maintain proper alkalinity, the content of calcium ions, magnesium ions, carbonate, phosphate radicals, hydroxyl ions and other ions in the water components is maintained at an optimal proportion, calcium and magnesium generate dispersed water slag sediment which is not adhered to the heating surface of the boiler, and the sediment is discharged out of the boiler along with the sewage discharge of the boiler to prevent scaling and corrosion. According to national standards such as GB/T1576 water quality of industrial boilers, the alkalinity of water is divided into full alkalinity and phenolphthalein alkalinity, wherein the phenolphthalein alkalinity is the amount of substances capable of accepting hydrogen ions measured when phenolphthalein is used as an indicator, and the full alkalinity is the amount of substances capable of accepting hydrogen ions measured when methyl orange or methyl red-methylene blue is used as an indicator.
At present, phenolphthalein alkalinity and/or full alkalinity in water is measured by taking phenolphthalein, methyl orange and the like as indicators, titrating with a standard acid solution with known concentration, determining a titration end point according to color change of a mixed solution, and calculating the phenolphthalein alkalinity and/or the full alkalinity according to the volume of the consumed standard acid solution. And because the color change pH range of the phenolphthalein is 8.2-10.0, and the color change pH range of the methyl orange is 3.1-4.4, the problem that different personnel judge different end points exists in the color change range of the indicator, so that errors in the use amount of the standard acid solution are easily caused, and errors exist in the calculation of the content of the phenolphthalein alkalinity and/or the full alkalinity.
Disclosure of Invention
Aiming at the defects in the prior art, the invention aims to provide a device and a method for measuring alkalinity in water samples such as boiler water, surface water and the like.
In order to achieve the above purposes, the invention adopts the technical scheme that: a water sample alkalinity measuring apparatus comprising:
a controller;
the measuring component comprises a water sample container, an emission module and a receiving module, wherein the water sample container is used for placing a water sample to be measured, the emission module and the receiving module are both electrically connected with the controller, and the emission module and the receiving module are oppositely arranged on two sides of the water sample container;
the sample adding component comprises a first quantitative pump, a second quantitative pump and a third quantitative pump, wherein the first quantitative pump is connected with a standard hydrochloric acid solution container and a water sample container through pipelines, the second quantitative pump is connected with a phenolphthalein solution container and a water sample container through pipelines, the third quantitative pump is connected with a methyl orange solution container and a water sample container through pipelines, and the first quantitative pump, the second quantitative pump and the third quantitative pump are all electrically connected with the controller.
Further, the controller comprises a main board, an output control board, a signal board, a display screen and a power supply, wherein the output control board, the signal board, the display screen and the power supply are all electrically connected with the main board; the output control board is electrically connected with the first fixed displacement pump, the second fixed displacement pump and the third fixed displacement pump and is used for controlling the actions of the first fixed displacement pump, the second fixed displacement pump and the third fixed displacement pump; the signal board is electrically connected with the transmitting module and the receiving module and is used for transmitting signals to the transmitting module and receiving signals to the receiving module.
Further, the measuring part also comprises a stirrer, and the stirrer is arranged at the bottom of the water sample container.
Further, the stirrer is electrically connected with the main board through the output control board.
Further, the signal board includes amplifier circuit, measuring circuit and the singlechip that connects gradually, and measuring circuit CAN measure receiving module's signal of telecommunication, and measuring circuit passes through inside CAN bus connection mainboard, and the mainboard has resistive touch screen interface and CAN _ bus communication interface.
Furthermore, the mainboard is an EPC-287I-L-T industrial control mainboard.
Further, the emitting module comprises a light emitting diode light source and a current limiting resistor which are connected in series, the light emitting diode light source can emit parallel light with fixed wavelength, and the receiving module comprises a photomultiplier.
Furthermore, the light emitting diode light source is a 490nm single cold color light emitting diode light source, and the resistance value of the current limiting resistor is 1000 omega.
A water sample alkalinity measuring method is carried out by using the water sample alkalinity measuring device, and comprises the following steps:
step (1), taking a water sample to be tested, placing the water sample into a water sample container, recording the volume of the water sample to be tested as V, and recording the receiving voltage value of the water sample to be tested as a blank voltage value A0；
Adding a phenolphthalein indicator into the water sample to be detected, and recording the receiving voltage value of the water sample to be detected as an initial voltage value A1；
Step (3) judging the initial voltage value A1And a blank voltage value A0If the difference value exceeds the preset range, firstly adding the hydrochloric acid solution until the receiving voltage value of the water sample to be detected is a first characteristic receiving voltage value, then adding the methyl orange indicator into the water sample to be detected, then adding the hydrochloric acid solution again until the receiving voltage value of the water sample to be detected is a second characteristic receiving voltage value, and recording the volume V of the hydrochloric acid solution added firstly1Volume V of hydrochloric acid solution added again2And concentration c of hydrochloric acid solution1(HCl), otherwise proceeding to step (4);
adding a methyl orange indicator into the water sample to be detected, then adding a hydrochloric acid solution to the receiving voltage value of the water sample to be detected to a second characteristic receiving voltage value, and recording the volume V of the added hydrochloric acid solution3And concentration c of hydrochloric acid solution2(HCl)。
Further, the specific step of determining whether the difference between the initial voltage value a1 and the blank voltage value a0 exceeds the preset range is:
if | A0-A1|≤0.2×A0Then, the initial voltage value A is determined1And a blank voltage value A0The difference value of (a) does not exceed a preset range;
if | A0-A1|＞0.2×A0Then, the initial voltage value A is determined1And a blank voltage value A0The difference value of (a) exceeds a preset range;
the predetermined range is 0.2 xA0。
Further, the first characteristic receiving voltage value is blank voltageValue A0。
Further, in the step (3), the calculation method of phenolphthalein alkalinity and total alkalinity in the water sample to be detected comprises the following steps:
JDP＝V1×c1(HCl)×1000/V；
JD＝(V1+V2)×c1(HCl)×1000/V；
JDPis phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V1is the volume of the hydrochloric acid solution added first, in milliliters (mL);
V2the volume of hydrochloric acid solution added again is in milliliters (mL);
c1(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
v is the volume of the water sample to be detected and is expressed in (mL).
Further, in the step (4), the calculation method of phenolphthalein alkalinity and total alkalinity in the water sample to be detected comprises the following steps:
JDP＝0；
JD＝(0+V3)×c2(HCl)×1000/V；
JDPis phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V3the volume of hydrochloric acid solution added is in milliliters (mL);
c2(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
v is the volume of the water sample to be detected and is expressed in (mL).
The invention has the following effects: by adopting the system and the method, the light rays emitted by the emitting module and the receiving module penetrate through the water sample to be measured, and the receiving voltage value of the water sample to be measured is measured, so that two titration end points are accurately identified through the change of the voltage value, automatic titration and measurement are realized, manual titration and manual judgment of the end points are completely replaced, the system and the method accord with relevant standards and methods, and the phenolphthalein alkalinity and the total alkalinity in the water quality can be accurately measured in real time; compared with the method of observing the color change of the indicator through eyes and determining the color change range of the indicator, the device and the method provided by the invention avoid the problem that different personnel judge different end points, ensure the measurement accuracy, have strong environmental adaptability and can realize online and real-time measurement.
Drawings
FIG. 1 is a schematic diagram of the structure of a water sample alkalinity measuring device according to the present invention;
FIG. 2 is a flow chart of the alkalinity measurement method of a water sample according to the present invention;
FIG. 3 is a titration curve of hydrochloric acid volume versus received voltage value in example 1 of the present invention;
FIG. 4 is a titration curve of hydrochloric acid volume versus received voltage value in example 2 of the present invention.
Detailed Description
The invention is further described with reference to the following figures and detailed description.
Example 1
As shown in fig. 1, the present embodiment discloses a water sample alkalinity measuring apparatus, which includes a controller 1, a measuring component 2 and a sample adding component 3. Wherein measuring part 2 includes water sample container 21, emission module 22 and receiving module 23, and water sample container 21 is used for placing the water sample that awaits measuring, and emission module 22 and receiving module 23 all are connected with controller 1 electricity, and emission module 22 and receiving module 23 set up the both sides at water sample container 21 relatively, and under the control of controller 1, emission module 22 can be stable sends the light of fixed wavelength, and light is followed by receiving module 23 and is received after passing the water sample that awaits measuring.
Further, the sample adding member 3 of the present embodiment includes a first quantitative pump 31, a second quantitative pump 32, and a third quantitative pump 33, and the first quantitative pump 31, the second quantitative pump 32, and the third quantitative pump 33 are all electrically connected to the controller 1; the first quantitative pump 31 is connected with the standard hydrochloric acid solution container and the water sample container 21 through pipelines, and can automatically add hydrochloric acid into the water sample container 21 under the control of the controller 1; the second quantitative pump 32 is connected with the phenolphthalein solution container and the water sample container 21 through a pipeline, and can automatically add phenolphthalein solution into the water sample container 21 under the control of the controller 1; the third quantitative pump 33 is connected with the methyl orange solution container and the water sample container 21 through a pipeline, and can automatically add the methyl orange solution into the water sample container 21 under the control of the controller 1.
Further, the controller 1 of the present embodiment includes a main board 11, an output control board 12, a signal board 13, a display 14 and a power supply 15, where the main board 11 is an EPC-287I-L-T industrial control main board, and of course, the main board may be replaced by another type of main board capable of implementing communication, measurement and control functions according to the reagent requirement. The output control board 12, the signal board 13, the display screen 14 and the power supply 15 are all electrically connected with the main board 11; the output control board 12 is electrically connected with the first fixed displacement pump 31, the second fixed displacement pump 32 and the third fixed displacement pump 33, and is used for controlling the actions of the first fixed displacement pump 31, the second fixed displacement pump 32 and the third fixed displacement pump 33; the signal board 13 is electrically connected to the transmitting module 22 and the receiving module 23, and is configured to transmit signals to the transmitting module 22 and receive signals to the receiving module 23.
Further, the measuring unit 2 of this embodiment further includes a stirrer, the stirrer is installed at the bottom of the water sample container 21, and the stirrer is electrically connected to the main board 11 through the output control board 12, and the stirrer can uniformly mix the water sample to be measured and the added reagent under the electrical control of the output control board 12.
Further, the emitting module 22 includes a light emitting diode light source and a current limiting resistor connected in series, the light emitting diode light source can emit parallel light with a fixed wavelength, and the receiving module 23 includes a photomultiplier tube. The light emitting diode light source is a 490nm single cold color light emitting diode light source, and the resistance value of the current limiting resistor is 1000 omega. The receiving module 23 can convert the light intensity absorbed by the water sample to be measured into an electrical signal, which is measured by the signal board 13.
Further, signal board 13 is including the amplifier circuit, measuring circuit and the singlechip that connect gradually, and measuring circuit CAN measure receiving module 23's signal of telecommunication, and measuring circuit passes through inside CAN bus connection mainboard 11, and mainboard 11 has resistive touch screen interface and CAN _ bus communication interface. The signal board 13 can amplify the signals collected by the transmitting module 22 and the receiving module 23, which facilitates capturing and observing data.
Example 2
The embodiment discloses a method for measuring alkalinity of a water sample, which is performed by using the device for measuring alkalinity of a water sample in embodiment 1, and comprises the following steps:
step (1), placing a water sample to be tested in a water sample container, recording the volume of the water sample to be tested as V, and recording the receiving voltage value of the water sample to be tested as a blank voltage value A0; specifically, after an emitting module and a receiving module with specific wavelengths of 490nm are preheated for 5 minutes, the accuracy of the emitting module and the receiving module is guaranteed not to be affected by temperature changes, and then 100mL of a water sample to be measured is taken and placed in a water sample container, namely, V is 100 mL.
Adding a phenolphthalein indicator into the water sample to be detected, and recording the receiving voltage value of the water sample to be detected as an initial voltage value A1(ii) a The phenolphthalein indicator is dripped through the second quantitative pump, so that the dripping speed and the dripping amount of the phenolphthalein indicator can be guaranteed.
Step (3) judging the initial voltage value A1And a blank voltage value A0Whether the difference value exceeds a preset range; specifically, calculate A0Subtract A1And A is0Subtract A1The absolute value of (a) and 0.2 times A0And (6) comparing. In the present embodiment, | A0-A1|＞0.2×A0Thus, the initial voltage value A is determined1And a blank voltage value A0The difference value of (a) is beyond the preset range, which shows that the receiving voltage value is obviously reduced after adding phenolphthalein, the mixed solution is pink after adding phenolphthalein, and the sample water to be detected contains phenolphthalein alkalinity. Then, the hydrochloric acid solution is added through the first quantitative pump until the receiving voltage value of the water sample to be detected is the first characteristic receiving voltage value, and the volume V of the hydrochloric acid solution added firstly is recorded at the moment1615 mul. Wherein the concentration of the hydrochloric acid solution is 0.05mol/L, and the first characteristic receiving voltage value is a blank voltage value A0. Adding a methyl orange indicator into the water sample to be detected through a third quantitative pump, and adding a hydrochloric acid solution again until the receiving voltage value of the water sample to be detected is a second characteristic receiving voltage value, wherein the second characteristic receiving voltage value is 180mV in the embodiment; record the volume V of the hydrochloric acid solution added again2＝0.645mL。
Then, in the step (3), the calculation method of the phenolphthalein alkalinity and the total alkalinity in the water sample to be detected is as follows:
JDP＝V1×c1(HCl)×1000/V＝0.615mL×0.05mol/L×1000/100mL＝0.3075mmol/L；
JD＝(V1+V2)×c1(HCl)×1000/V＝(0.615+0.645)mL×0.05mol/L×1000/100mL＝0.630mmol/L；
JDPis phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V1is the volume of the hydrochloric acid solution added first, in milliliters (mL);
V2the volume of hydrochloric acid solution added again is in milliliters (mL);
c1(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
v is the volume of the water sample to be detected and is expressed in (mL).
The titration curve of hydrochloric acid volume versus received voltage value in this example is shown in FIG. 3.
Example 3
As another embodiment of the present invention, this embodiment also discloses a method for measuring alkalinity of a water sample, which is performed by using the apparatus for measuring alkalinity of a water sample in embodiment 1, and includes the following steps:
step (1), taking a water sample to be tested, placing the water sample into a water sample container, recording the volume of the water sample to be tested as V, and recording the receiving voltage value of the water sample to be tested as a blank voltage value A0(ii) a Specifically, after an emitting module and a receiving module with specific wavelengths of 490nm are preheated for 5 minutes, the accuracy of the emitting module and the receiving module is guaranteed not to be affected by temperature changes, and then 100mL of a water sample to be measured is taken and placed in a water sample container, namely, V is 100 mL.
Adding a phenolphthalein indicator into the water sample to be detected, and recording the receiving voltage value of the water sample to be detected as an initial voltage value A1(ii) a Wherein the phenolphthalein indicator is dripped through the second quantitative pump, so that the phenolphthalein indicator can be ensuredThe dropping rate and the dropping amount.
Step (3) judging the initial voltage value A1And a blank voltage value A0Whether the difference value exceeds a preset range; specifically, calculate A0Subtract A1And A is0Subtract A1The absolute value of (a) and 0.2 times A0And (6) comparing. In the present embodiment, | A0-A1|≤0.2×A0Thus, the initial voltage value A is determined1And a blank voltage value A0The difference value of (A) does not exceed the preset range, which indicates that the receiving voltage value is not obviously reduced after adding the phenolphthalein, and indicates that the sample water to be tested does not contain the alkalinity of the phenolphthalein and only contains the total alkalinity. Then, adding a methyl orange indicator into the water sample to be detected through the third quantitative pump, and then adding a hydrochloric acid solution through the first quantitative pump until the receiving voltage value of the water sample to be detected is a second characteristic receiving voltage value, wherein in this embodiment, the concentration of the hydrochloric acid solution is 0.1mol/L, and the second characteristic receiving voltage value is 180 mV; record the volume V of the hydrochloric acid solution added3＝4.930mL。
Then, in the step (3), the calculation method of the phenolphthalein alkalinity and the total alkalinity in the water sample to be detected is as follows:
JDP＝0mmol/L；
JD＝(0+V3)×c3(HCl)×1000/V＝(0+4.930)mL×0.1mol/L×1000/100mL＝4.930mmol/L；
JDPis phenolphthalein alkalinity in millimoles per liter (mmol/L);
JD is the full alkalinity in millimoles per liter (mmol/L);
V1is the volume of the hydrochloric acid solution added first, in milliliters (mL);
V2the volume of hydrochloric acid solution added again is in milliliters (mL);
c1(HCl) is the concentration of the hydrochloric acid solution in moles per liter (mol/L);
v is the volume of the water sample to be detected and is expressed in (mL).
The titration curve of hydrochloric acid volume versus received voltage value in this example is shown in FIG. 4.
It will be appreciated by those skilled in the art that the method and system of the present invention are not limited to the embodiments illustrated in the detailed description, which is intended to be illustrative of the invention and is not intended to be limiting. Other embodiments will be apparent to those skilled in the art from the following detailed description, which is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention as defined by the appended claims.
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