KR100328979B1 - Multi-channel apparatus for measuring pH/Ion - Google Patents

Abstract

PURPOSE: A multiple channel pH/ion detecting apparatus is provided, thereby rapidly detecting pH/ion of numerous samples. CONSTITUTION: A multiple channel pH/ion detecting apparatus comprises an external casing; a circuit board with multiple introducing channels within the external casing; a plurality of introducing ports connected to the introducing channels and positioned on the external casing; a plurality of probes(103) for detecting the voltage of chemical samples(121) and connected to the port; an analogue-digital converter for converting the voltage detected by the probe(103) from analogue value to digital value; a pH/ion value calculating device for calculating the digital value of the voltage converted by the analogue-digital converter to pH/ion value using a software; a displaying portion(112) for displaying the calculated pH/ion value; and a controlling portion(110).

Description

Multi-channel apparatus for measuring pH / Ion

The present invention relates to a multi-channel pH / ion measuring device for measuring the concentration of hydrogen ions (pH) and the concentration of dissolved ions (Ion), and at the same time has a structure that can measure the pH / ion of a number of samples The present invention relates to a pH / Ion measurement device that can shorten time and improve measurement efficiency, and is used in connection with analysis software and a computer to display a plurality of measurements simultaneously and to easily store and use the measurement values.

The pH / Ion measuring device uses integrated software to manage the analysis system, enabling integrated management of the entire system and independent operation of each channel, centralized simultaneous on-line management, and long-term observation. And control is possible.

In general, for the electrochemical detection of dissolved cations, anions and gas ions, potentiometry is widely used to measure the potential change according to the activity (or concentration) of ions. Potentiometric analysis is based on measuring the potential of an electrochemical cell in the absence of current. The concentration of ions is determined directly from the potential of the ion selective electrode that selectively reacts with the ions to be analyzed. Such electrodes are relatively unaffected by other ions and provide a quick and convenient way to quantify many important anions, cations and gases. The effect of activity (or concentration) on the electrode potential is represented by the Nernst equation:

Dip the appropriate indicator and reference electrodes into the solution to be analyzed, and determine the concentration of the analyte by measuring the potential. The electrode must be calibrated with the standard solution. E _cell vs. Calibration lines, such as log concentration, can be prepared by making a series of standard solutions and measuring the potential.

A variety of membrane electrodes are available on the market for the rapid and selective quantitation of various cations and anions by potentiometric measurements. The membrane electrode used as the indicator electrode is also called an ion-selective electrode (ISE) because of its high selectivity to dissolved ions. ISE is prepared by immobilizing a sensitive material that selectively reacts with an ion to be analyzed on a polymer support, or by using a gas-selective permeable membrane or a solid sensitive material.

All ion-selective membranes have a common property, which is their sensitivity and selectivity to any cation or anion. Dissolved cations (NH ₄ ⁺ , Cd ²⁺ , Cu ²⁺ , Pb ²⁺ , Li ⁺ , NO _X , K ⁺ , Ag ⁺ , Na ⁺ , Ca ²⁺ , Mg ⁺² , X ⁺ ), anions ^{_{(Br -, CO 3 2-,}} Cl -, CN -, F -, BF 4 -, I -, NO 3 -, ClO 4 -, S 2-, X -) and a gas (NH _3, CO ₂₎ Since ISE has been developed, it is possible to measure their concentration easily and quickly by potentiometric method.

Hereinafter, an analysis method using ISE will be introduced.

1) A typical ion-selective electrode includes a glass electrode for pH measurement that measures hydrogen ion concentration. The tip of the glass electrode consists of a thin glass membrane that is sensitive to the pH of the solution. The glass restraint contains silver lead coated with AgCl and filled with 0.1 M hydrochloric acid solution saturated with silver chloride. Since the activity (a _{H +} ) of hydrogen ions inside the membrane is kept constant by HCl, the cell potential is sensitive to the pH of the sample solution. Where the potential for concentration in hydrogen ions is defined as

E = E ^* + 0.0591 pH

The pH meter measures the potential of the glass electrode relative to the external reference electrode and displays this output on a meter scale calibrated with a pH scale. The pH meter does not know the relationship with pH to measure the electrochemical cell potential, so it should be standardized to show an appropriate pH value. Standardization utilizes one or more standard buffer solutions of known pH.

2) For example, a calcium ion-selective electrode uses a polymer membrane immobilized with Ionophore, a compound capable of selectively ion exchange with calcium ions, and a silver / silver chloride electrode used in a pH electrode as a reference electrode. According to the concentration of calcium ions, the potential difference occurring at the calcium ion-selective electrode may be expressed as follows.

Using a calcium ion standard solution that knows the concentration accurately, the linear equation is obtained from the potential of the calcium ion-selective electrode according to the calcium ion concentration. The electrode is placed in a calcium ion sample solution and the potential is calculated. Then, the concentration of calcium ion is obtained from a straight line.

In general, in the case of hydrogen ions, the measured value is displayed on the device by converting the generated potential into a pH scale, and the other dissolved ions represent the measured value in potential (mV units). The concentrations of other cations, anions and dissolved gases that are dissolved can also be measured from the potential of the ISE, such as hydrogen ions and calcium ions.

1 is a perspective view of a conventional pH / ion measuring device. As shown in this figure, the conventional pH / Ion measuring device is composed of a measuring device body 1 and a voltage measuring probe 3 connected to the measuring device body 1.

The measuring device body 1 has a structure in which a circuit board is mounted inside the outer casing. An analog-to-digital converter (AD converter, not shown) is mounted on the circuit board so that the analog value of the measured voltage value measured by the probe 3 can be converted into a digital value. Thus, the system software is installed so that the measured voltage value is converted into a digital value and then displayed via a display unit provided on the outer surface of the outer casing.

Then, the probe 3 is supported by the support 2 mounted on the outer casing, and is contained in the container 7 in which the chemical sample 8 is contained, thereby measuring the voltage value of the chemical sample 8. I can do it.

With this configuration, when the pH / Ion of the chemical sample 8 contained in the container 7 is to be measured, the probe 5 is placed in the container 7 and the chemical sample 8 in the container 7 Make contact. At this time, the probe 5 measures the voltage value of the chemical sample 8 and transmits the voltage value to the measuring device body 1. Thus, the voltage value is input to a circuit board (not shown) inside the measuring device body 1, and the measured analog voltage value is converted into a digital value by the AD converter. The voltage value converted into a digital value is converted into pH / Ion value again through software, and displayed on the display unit 5. Accordingly, the experimenter can know the pH / Ion value of the chemical sample 8 by looking at the numerical value displayed through the display unit 5.

By the way, the conventional pH / Ion measuring device is formed by a single port connected to the ISE probe, it is possible to measure only the pH / Ion of one chemical sample at a time. In addition, the developed multichannel analyzer has about 4 probe input terminals, but each input terminal cannot perform the analysis independently, but only a simple connection function that can be used with a separate single channel pH / Ion developed previously. Perform. Therefore, when trying to measure a large number of chemical samples, there is a problem that takes a lot of measurement time by performing one measurement at a time.

Therefore, the present invention has been made to solve the above problems, and at the same time has a multi-channel structure that can measure the pH / Ion of a plurality of samples can shorten the measurement time and improve the measurement efficiency, analysis software And a pH / Ion measurement device that is used in connection with a computer to display a plurality of measurements simultaneously and to facilitate storage and utilization of the measurements. By using the software for comprehensive management of the analysis system, the integrated management of the entire system and each channel can be operated independently, and the centralized on-line long-term observation can be managed and controlled.

1-a perspective view of a conventional pH / ion measuring device.

2 is a perspective view of a multi-channel pH / ion measuring device according to the present invention.

3-2 are circuit diagrams of main parts of the measuring apparatus of FIG.

4-2 is a state diagram illustrating the display of the pH / Ion values measured by the monitor of FIG.

5-control block diagram of software for the operation of the pH / Ion measuring device according to the invention.

<Description of Symbols for Main Parts of Drawings>

101: measuring device body 103: probe

104: input port 106: connection line

109: input channel 110: computer body

111: temperature sensor 112: monitor

120 container 121 chemical sample

Multi-channel pH / Ion measuring apparatus for measuring the pH / Ion of a plurality of chemical samples according to the present invention for achieving the above object, the outer casing; A circuit board accommodated in the outer casing and having a plurality of input channels formed therein; A plurality of input ports installed on the outer casing and connected to the input channels; A plurality of measurement probes each connected to an input port for measuring a voltage value of a chemical sample; An analog-digital converter for converting an analog value of the voltage value measured by the measurement probe into a digital value; A conversion device for converting the digital value of the voltage value converted by the analog-digital converter into a pH / Ion value by software conversion; A control unit for controlling, operating, calibrating, converting data, storing and displaying the measured value of the multichannel pH / Ion measuring device, including a display unit for displaying the pH / Ion value converted by the conversion device, and software for controlling the system. By using a plurality of input ports, the measured value of each chemical sample is characterized in that for displaying the pH / Ion value, respectively.

Here, the analog-to-digital converter is built in the computer body, the conversion device is driven by a program installed in the computer body, it is preferable to be displayed on the monitor connected to the computer body.

The external casing is equipped with a temperature sensor for sensing the external temperature, and the analog-to-digital converter converts the analog value of the voltage value into a compensation value corresponding to the external temperature measured by the temperature sensor and converts it into a digital value. More preferred.

Accordingly, it is possible to measure the pH / Ion of a plurality of samples at the same time to shorten the measurement time and improve the measurement efficiency. In addition, a plurality of measurement values are displayed through a monitor by being used in connection with a computer, thereby providing various display images.

Hereinafter, the present invention will be described in more detail with reference to the accompanying drawings.

2 is a perspective view of a pH / Ion measuring device according to the present invention. As shown in this figure, the pH / Ion measuring device for measuring the pH / Ion of the chemical sample 121, similar to the conventional pH / Ion measuring device, the measuring device body 101 and the measuring device body ( And a voltage measuring probe (103) connected to 101).

A plurality of input ports 104, for example 16 input ports 104, are formed in the outer casing, which forms the outline of the measuring device body 101, and these input ports 104 are connected to the connection line 106. One end is connected, and the other end of the connecting line 106 is connected to the probe 103. In addition, a separate connection port is formed in the measuring device body 101, and the measuring device body 101 is connected to the main body of the computer by a connection wire to transmit a signal to the computer main body 110. .

A circuit board is mounted inside the outer casing of the measuring device body 101, and a plurality of input channels 109, for example, 16 input channels 109 are formed on the circuit board, respectively. 109 are connected to the input port 104 formed in the outer casing in a one-to-one manner. Thus, a plurality of measurement probes 103 connected to the input port 104 and capable of measuring the voltage value of the chemical sample 121 measure the voltage value of the chemical sample 121 contained in the container 120 to measure the measuring device. When transmitting to the body portion 101, as shown in Figure 3, the measured voltage value is to be input to the input channel 109 of the measuring device body portion 101 through the input port 104.

The computer main body 110 connected to the measuring device body 101 is equipped with an analog-to-digital converter and software for converting an analog value of a voltage value measured by the measuring probe 103 into a digital value. Thus, the analog-to-digital converter receives an analog value from the input channel 109 on the circuit board of the measuring device body 101 and converts it to digital. At this time, the temperature sensor 111 installed in the outer casing senses the external temperature, and a compensation value corresponding to the external temperature is input to the analog-digital converter, whereby the analog-digital converter compensates the analog value with the compensation value. To convert it to a digital value.

In addition, a computer (110) is provided with a conversion device (software) for converting the digital value of the voltage value converted by the analog-to-digital converter into a pH / Ion value. The conversion apparatus exists as a program in a hard disk, which is an auxiliary memory device mounted inside the computer main body 110. Thus, the converting apparatus converts the digital value into a pH / Ion value, and this converted value can be displayed through the monitor 112, as shown in FIG.

Hereinafter will be described the operation and effect of the pH / ion measuring device according to the present invention.

Using the multi-channel pH / ion measuring device described above, when the experimenter wants to measure the pH / ion of different chemical samples 121 contained in the plurality of containers 120, the input of the measuring device body 101 A plurality of probes 103, for example sixteen probes 103, each connected to the port 104, are brought into contact with the chemical sample 121 contained in the sixteen vessels 120. At this time, each probe 103 measures the voltage value of the chemical sample 121 and transmits the measured value to each input port 104 side of the measuring device body 101 through the connecting line 106. Thus, the voltage value of the chemical sample 121 input through each input port 104 passes through each input channel 109 and is then input to a digital-analog converter mounted on the computer main body 110. The digital-to-analog converter converts each of the measured voltage analog values into digital values, and in this conversion step, a compensation value corresponding to the external temperature measured by the temperature sensor 111 is compensated, and the digital values are respectively converted. Is calculated.

Each calculated digital value is converted into a pH / Ion value by a program installed in a hard disk in the computer main body 110, respectively. The converted pH / Ion value is displayed through the monitor 112 as shown in FIG. 4, so that the measurer can intuitively recognize the pH / Ion value of the chemical sample 121.

Here, by displaying a plurality of pH / Ion measurements at the same time on the monitor 112, the measurer can measure many kinds of chemical samples 121 at the same time to know the value. Accordingly, the measurement time of the chemical sample 121 can be shortened and the measurement efficiency can be improved. In addition, since the measuring device is connected to the computer to operate, the pH / Ion value can be variously converted to other values, it is possible to be applied to other formulas and equations that require the pH / Ion value, The display may be represented in various ways.

5 is a control block diagram of software for the operation of the pH / Ion measuring device according to the present invention. As shown in this figure, the software for operating the measuring device has an automatic calibration function and an environment setting function. Thus, after calibration and configuration is preceded, mV / pH is measured and the measured mV / pH is displayed on the screen. Accordingly, mV / pH is effectively measured and displayed on the screen.

As described above, according to the multi-channel pH / Ion measuring apparatus according to the present invention, it has a structure that can measure the pH / Ion of a plurality of samples at the same time can shorten the measurement time and improve the measurement efficiency, analysis Used in conjunction with software and computers, multiple measurements can be displayed simultaneously, making it easy to store and use measurements. In addition, integrated management of the analysis system and each channel can be operated independently using the software for comprehensive management of the analysis system, and centralized on-line management and control is possible through long-term observation.

Claims (3)

In the multi-channel pH / Ion measuring device for simultaneously measuring the pH / Ion of a plurality of chemical samples 121, Outer casing; A circuit board accommodated in the outer casing and having a plurality of input channels 109 formed therein; A plurality of input ports 104 installed on the outer casing and connected to the input channel 109; A plurality of measurement probes 103 connected to the input ports 104 and capable of measuring voltage values of the chemical sample 121; An analog-digital converter for converting an analog value of the voltage value measured by the measuring probe 103 into a digital value; A conversion device for converting the digital value of the voltage value converted by the analog-digital converter into a pH / Ion value by software conversion; A display unit which displays the pH / Ion value converted by the conversion device; And And a control unit for controlling, operating, calibrating, converting, storing, and displaying measurement values of the multichannel pH / Ion measuring device with system control software. PH / Ion measuring device, characterized in that for displaying the measured value of each chemical sample 121 input through the plurality of input ports 104 as a pH / Ion value through software. The method of claim 1, wherein the analog-to-digital converter is built in the computer body, the conversion device is driven by a program installed in the computer body, it is displayed via a monitor 112 connected to the computer body. Multichannel pH / Ion measuring device. According to claim 1 or 2, wherein the outer casing is provided with a temperature sensor 111 that can sense the external temperature, the analog-to-digital converter is the temperature sensor 111 to convert the analog value of the voltage value Multi-channel pH / ion measuring device, characterized in that for converting to a digital value by compensating with a compensation value corresponding to the external temperature measured by.