KR100428751B1 - TDS/Salt-Meter - Google Patents

Abstract

PURPOSE: A TDS(Total Dissolved Solids)/salt-measuring instrument is provided to measure the concentration of salt and the concentration of TDS with one measuring instrument. CONSTITUTION: An ion concentration-measuring instrument comprises two electrodes(110) coming in contact with a sample; a circuit part(120) supplying a current to two terminals and having a resistance value and capacitance; a frequency-calculating part(130) finding the frequency of the sample by using the resistance value of the sample in which the current flows; operation parts(140,145) finding the ion concentration of the sample corresponding to the frequency of the sample from a table numerically formularizing the ion concentration of calibration solution previously stored; an output part indicating the ion concentration of the sample; and a sampling auxiliary unit. The sampling auxiliary unit includes an opening inserted in the electrodes; a holding part fixing a side of the inserted part to fix the inserted part to the inside of a sampling part in a close contact state; and the sampling part connected to the opening. The sampling part keeps predetermined quantity of the sample.

Description

TDS / Salt Meter {TDS / Salt-Meter}

The present invention relates to ion concentration and portable TDS (hereinafter referred to as 'TDS') / salinometer, and more specifically, to the ion concentration, salinity (hereinafter salinity, salinity) of a sample using a frequency conversion analysis method using conductivity method And TDS / salin meter for measuring the TDS and salinity of a sample by measuring the frequency according to the concentration of TDS and then comparing the frequency according to the concentration of salinity and TDS standard solution.

In general, a sensor, also called a detection element, refers to a device that detects changes in physical and stoichiometric amounts. When sensors are developed, they can be classified into physical sensors that measure physical quantities and chemical sensors that measure chemical substances. have.

Various analytical methods have been developed to identify the types and structures of various chemical substances in unknown samples and to quantitatively measure the amount of these substances by applying this sensor technology. Methods are being developed to accurately analyze these excellent and trace amounts of samples. In particular, as the need for accurate and short time sample analysis for process automation, quality control, medical analysis, and analysis of environmental samples increases, there is a growing interest in the development of methods and devices for easy analysis of chemicals. It is increasing.

Most materials in nature are neutral, but atoms or molecules possess or lose excess electrons, which are also present in large quantities in the form of positive or negative ions in water or other solvents. Because these substances are chemically active, they need to be accurately determined and controlled in clinical healthcare and diagnostics, food, environment and process control.

The most widely used method for measuring such ions is ion chromatography, precipitation titration, atomic absorption or atomic emission, and ion selective electrodes. Potentiometry, conductance using conductivity, and the like.

Among the devices using atomic absorption / luminescence method, precipitation titration method, and ion chromatography method, the device is expensive, the pretreatment process of the sample is complicated, and it is not easy to carry, so it is not easy to measure the site. Due to the proficiency difference, and because the focus of the existing analyzer is designed to be suitable for microanalysis, errors due to dilution may occur in the large amount analysis.

On the other hand, as one of the electrochemical methods for measuring the potential difference, the amount of electricity, and the change in conductivity due to the electrode reaction in solution, the conductivity method for measuring the electrical resistance between electrodes is simple and the operation time is short. In addition, mass analysis is easy, and unlike the spectroscopic analysis method, it is not affected by turbidity of the sample, so that no pretreatment step of the sample is required, and the manufacture of the analysis device is relatively simple, so that the price of the device is lower than that of other analysis equipment. It has an advantage.

Therefore, the conductivity analysis method is not only used for water quality management and analysis, such as purification facilities for industrial water, water quality management facilities for water and sewage, and boiler water management, but also for process control and environmental analysis in food and industrial chemistry. Widely applied.

The most common ions in everyday life include hydrogen ions (H ⁺ ), which determine acid-alkaline properties, various alkali ions (Na ⁺ , K ⁺ , Ca ²⁺ , Mg ^2+, etc.), heavy metal ions (Pb ²⁺ , Cd ^2+, Cu ^2+, etc.), halogen ions ^{(F -, Cl -, Br} -, I -), atomic ions _{^{(NH 4 +, NO 3 -}} , SO 4 2- , etc.), and the like need to measure with a high degree of ion There are a lot of them.

In particular, salts composed of Na ⁺ and Cl ^- ions are contained in the daily food, so in the case of patients with hypertension or chronic renal failure, the amount of salt intake should be controlled. However, the average daily salt intake of Korean people is about 20mg, which is more than twice the intake of Westerners, which acts as a factor in the incidence of diseases such as hypertension. Therefore, controlling the amount of salt intake not only for hypertension patients but also for the general public can be said to be very important for maintaining health.

TDS stands for Total Dissolved Solids. If contaminated water is filtered through the filter paper, some of the filter paper is filtered and passed through. The hanging on the filter paper is called SS (Suspended Solids), and the dissolved material in the solution that passes through the filter paper is called dissolved solids (TDS).

Total dissolved solids refers to the total amount of solids dissolved in water, including minerals such as calcium and magnesium iron. In other words, TDS is used to measure how much solids such as minerals are dissolved in water. In particular, TDS is used as an important indicator for scale generation of boiler tubes. However, measuring organic and inorganic substances in water can be very embarrassing, and measuring volatiles (Volatile Solute) or dissolved gases generated during oxidation is not practical in terms of water quality management, which requires promptness. It's work. Therefore, in terms of measurement efficiency, the TDS value is measured as the electrical conductivity because it is proportional to the electrical conductivity.

However, in the case of the conventional measuring device using a commercially available conductivity method, most of the measured values are inaccurate and expensive, and localization is urgently needed since the whole quantity depends on imports.

Conventional salinometers can only measure salinity concentrations using frequency conversion depending on the salinity concentrations of standard solutions. However, in real life, there is a need to measure not only salinity concentration but also TDS concentration together, but there is a problem in that there is no measuring instrument that can measure salinity and TDS concentration together with one meter.

In addition, in order to correct the measurement error caused by the temperature change in the same sample, it is necessary to accurately measure the temperature of the sample. In the conventional measuring device, since the temperature sensor is not provided differently, the measured value was inaccurate.

In the conventional measuring device, when the temperature of the sample is high, there is a risk of removing part of the body (finger, hand, etc.) when the electrode of the measuring instrument is put into the sample, and using a different instrument to collect a part of the sample. Then, when measuring the sample collected there was a problem such as the preparation of the container, an error occurs due to the change of the temperature of the sample.

Therefore, the technical problem to be achieved by the present invention is to provide a TDS / salinity meter that can measure not only the salinity concentration but also the TDS concentration with the same meter.

Another technical problem of the present invention is to provide a TDS / salinity meter that can more accurately correct the measurement error caused by the temperature change by measuring the temperature of the sample accurately.

Another technical problem of the present invention is to provide a TDS / salinometer which can measure the concentration of a sample even if the sample is a high temperature without risk to the body and a large temperature error.

1 is a block diagram of a TDS / salinometer according to an embodiment of the present invention,

2 is a view showing the electrode and the circuit portion of the TDS / salinometer according to an embodiment of the present invention,

Figure 3 is a block diagram showing the configuration of a TDS / salinometer according to an embodiment of the present invention,

Figure 4 is a graph showing the frequency characteristics according to the concentration change of the salinity standard solution of the TDS / salinity measuring instrument according to an embodiment of the present invention,

Figure 5 is a graph showing the precision between the measuring by repeating the measurement according to the salinity concentration changes in the TDS / salinity measuring instrument of one embodiment of the present invention,

Figure 6 is a graph showing the measured salinity according to the temperature change with a portable TDS / salinometer which is an embodiment of the present invention,

7 is a graph showing the frequency change characteristics according to the TDS concentration change of the TDS standard solution,

8 is a graph showing the precision between the measuring by repeating the measurement with a TDS / salinometer which is an embodiment of the present invention,

Figure 9 is a graph showing the measured value of the TDS according to the temperature change with a TDS / salinometer which is an embodiment of the present invention,

10 is a view showing the appearance of the TDS / salinometer according to an embodiment of the present invention,

11 illustrates a circuit of a TDS / salin measuring device according to an embodiment of the present invention;

12A and 12B are diagrams of a sampling aid according to an embodiment of the present invention.

According to an aspect of the present invention, an ion concentration meter includes two electrodes in contact with a sample; A circuit unit supplying current to the two terminals and having a predetermined resistance value and capacitance; A frequency calculator which calculates a frequency of the sample using a resistance value of the sample through which the current flows; A calculation unit for obtaining the ion concentration of the sample corresponding to the frequency of the sample from a table in which the ion concentration of the standard solution stored in advance is formulated; An output unit displaying ion concentration of the sample; And an opening inserted into the electrode portion, connected to the opening portion, a holding portion fixing one side of the inserted portion so as to be in close contact with the inside of the collecting portion, and connected to the opening portion. And a sampling aid including a sampling part having a predetermined amount of the sample. A TDS / salin measuring device according to the present invention for achieving the above technical problem includes two electrodes in contact with a sample; A circuit unit supplying current to the two terminals and having a predetermined resistance value and capacitance; A frequency calculator which calculates a frequency of the sample using the resistance of the sample through which the current flows; A sensor unit for sensing a temperature of a sample using a temperature sensor mounted on one of the electrodes; The salinity concentration of the sample corresponding to the frequency of the sample is obtained from a table formulating the concentration of the pre-stored frequency-saline standard solution, and the salinity of the sample is corrected by reflecting the measurement error according to the temperature of the sample detected by the sensor unit. A first calculation unit to perform; The TDS concentration of the sample corresponding to the frequency of the sample is obtained from a table formulating the concentration of the pre-stored frequency-TDS standard solution, and the TDS concentration of the sample is corrected by reflecting the measurement error according to the temperature of the sample detected by the sensor unit. A second calculating unit; A keypad including a mode selection key and a hold (test) key; And a control unit which transmits the corrected TDS concentration or salinity concentration and temperature of the sample according to the operation of the mode selection key to the output unit, and displays the measured value on the output unit for a predetermined time when the hold (test) key is operated. Characterized by including.

According to another aspect of the present invention, there is provided a TDS / salin measuring device including an opening into which an electrode part of the TDS / salin measuring device is inserted; A holding part connected to the opening and fixing one side of the inserted part to closely contact the inserted part to an inside of a collecting part; And a sampling unit connected to the opening and configured to hold a predetermined amount of the sample.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be noted that in the following description, only parts necessary for understanding the operation according to the present invention will be described, and descriptions of other parts will be omitted so as not to distract from the gist of the present invention.

1 is a block diagram showing the configuration of a TDS / salinometer according to an embodiment of the present invention.

First, a predetermined current flows through the electrode 10 to the sample. When various ions exist in the sample, current flows through the electrode.

Electrode is a metal electrode material (Au, Cu, Ag, Pt, etc.), preferably produced using the electrochemical properties (conductivity, chemical resistance, durability, etc.) is excellent, and the economical efficiency, gold (Au) is harmless to the human body do.

The sensor unit 15 senses the temperature of the sample using a temperature sensor mounted inside one of the two electrodes. The temperature of the sample is sensed using a temperature sensor mounted on one of the metal electrodes, which facilitates heat transfer, so that the temperature of the sample can be measured accurately and simply. The sensor unit is an additional factor to obtain a more accurate ion concentration of the sample.

The circuit unit 20 includes a power supply and a resistor and a capacitor for measuring conductivity of the sample.

2 is a diagram illustrating a configuration of an electrode and a circuit unit. Current flows in the sample (via the electrode) and in the circuitry.

Electrical conductivity refers to the degree to which a solution can carry an electric current. It is an item that can quickly evaluate the ionic strength in a solution. It is expressed as the inverse of the electrical resistance in ohm-1 or mho. It is commonly used. The measuring principle takes advantage of the fact that when a constant voltage is applied to two electrodes in a solution, the applied voltage causes current to flow, and the magnitude of the current flowing depends on the conductivity of the solution.

Can be expressed as: Is the resistance, l is the distance between two electrodes (cm), and A is the cross-sectional area (cm 2).

L = 1 / R = (A / l) * K

Becomes Where K (= 1 / ) Is the non-conductivity (mho / cm) and the cell size is constant when the same measuring system is used, so the distance and cross-sectional area between two electrodes can be ignored.

That is, since a current flows in the sample and the circuit part, the resistance value can be obtained by Ohm's law.

R (t) = R (sample) + R (circuit)

Where R (t) is the total resistance, R (sample) is the resistance of the sample, and R (circuit) is the resistance inside the circuit section. And the capacitor value of the circuit portion can be represented by C.

2 is a view showing the electrode and the circuit portion of the TDS / salinometer according to an embodiment of the present invention. It is relaxation oscillator circuits using internal resistance R, capacitor C, and NAND Schmitt trigger. 74HC132 is used in this circuit.

The square wave is output by the continuous charging and discharging of the capacitor.

The exponential charge and discharge of this capacitor was analyzed to derive an equation for obtaining the output square wave period.

UTP (Upper Trip Point) has a value of V _H and LTP (Lower Trip Point) has a value of V _L. The basic switching equation that applies to any RC circuit is

v = v _i + (v _f -v _i ) (1-e ^{-t / RC} )

Can be expressed as

v = instantaneous capacitor voltage

v _i = initial capacitor voltage

v _f = final capacitor voltage

t = charging time

RC = time constant

Indicates.

In Figure 2 the capacitor begins to charge from V _L (initial value) and ends at V _H. The final value for the capacitor voltage is Vsat, and the charge time of the capacitor is T / 2 (half cycle). If you apply this to the above equation

V _H = V _L + (V _sat + V _H ) (1-e ^{-T / 2RC} )

Simply

Taking an antilog, the above expression

Therefore, the frequency

The calculation unit 40 obtains the ion concentration of the sample corresponding to the frequency of the sample from the table in which the ion concentration stored in advance is modified. That is, the frequency according to the ion concentration of the standard solution is measured through experiments and then formulated with respect to the ion concentration and frequency. Then, the frequency of the sample is compared with that of the standard solution, and the ion concentration of the standard solution corresponding to the frequency of the standard solution is the ion concentration of the sample.

Since the conductivity of the solution changes with the temperature of the solution, that is, the conductivity value increases as the temperature increases, the compensator 45 corrects the frequency change according to the temperature of the sample to correct the ion concentration of the sample. That is, the frequency change according to the temperature change of the standard solution is formulated, and if the temperature of the sample is 30 ℃, the frequency corresponding to the difference of 5 ℃ is subtracted, and if the sample temperature is 20 ℃, it corresponds to the difference of 5 ℃. Correct the measurement error according to the temperature change of the sample by adding frequency.

The output unit 50 displays the ion concentration of the corrected sample. In addition, when the temperature sensor unit is included, the ion concentration and temperature of the corrected sample can be displayed.

Figure 3 is a block diagram showing the configuration of a TDS / salinometer according to an embodiment of the present invention.

The electrode 110, the sensor unit 115, the circuit unit 120, and the frequency calculator 130 are replaced with the description of the TDS / salin meter shown in FIG. 1.

The first calculation unit 140 obtains the salinity concentration of the sample corresponding to the frequency of the sample from a table in which the concentration of the frequency-salin standard solution is stored in advance, and the salinity error according to the temperature of the sample detected by the sensor unit. Correct the salinity of the sample by reflecting. The correction of the temperature-dependent error uses the method described above.

Figure 4 is a graph showing the frequency characteristics according to the change in the concentration of the salt standard solution of the TDS / salinometer of an embodiment of the present invention.

In order to investigate the salinity sensitivity of the TDS / salinity measuring device of an embodiment of the present invention using a salt standard solution (0.01% to 5.0%) of which the exact concentration is known to investigate the frequency characteristics of the salinity change. 4 is the concentration (%) of the salt standard solution, the vertical axis represents the frequency (Hz). The frequency change according to the salinity change was programmed after obtaining the most accurate equation through curve fitting. According to the formula, when the salt concentration is 1%, the frequency is 1000 Hz. Based on this, a table formulating the concentration of the frequency-standard solution is prepared and used in the first calculation unit.

Figure 5 is a graph showing the precision between the measuring by repeating the measurement according to the salinity change with a TDS / salinity measuring instrument of an embodiment of the present invention.

In order to investigate the accuracy of the repeated measurement and measurement period according to the salinity change of the TDS / salin measuring device, which is an embodiment of the present invention, five measuring devices using a salinity standard solution (0.01% to 5.0%) of which a known concentration is known Ten measurements were taken. 5 is the concentration (%) of the salinity standard solution, and the vertical axis is the measured value of the salinity standard solution measured by the portable TDS / salinity meter according to an embodiment of the present invention. As shown in FIG. 5, the deviation of the measured value was found to have a value within ± 10% of the measured value as a whole, and also to maintain linearity.

Figure 6 is a graph showing the measured salinity according to the temperature change with a portable TDS / salinometer which is an embodiment of the present invention.

In an embodiment of the present invention, in order to investigate the precision of salinity concentration measurement according to temperature change with a portable TDS / salinometer, a temperature range of 0 ° C. to 70 ° C. using a saline standard solution (0.01% to 5.0%) of which the concentration is already known. 10 measurements were made at. 6 is the concentration (%) of the salinity standard solution, and the vertical axis is the salinity concentration (%) of the standard solution measured by the portable TDS / salin measuring device according to one embodiment of the present invention. As shown in FIG. 6, the deviation of the measured value was found to have a value within ± 10% of the measured value as a whole, and also to maintain linearity.

The second calculating unit 145 obtains the TDS concentration of the sample corresponding to the frequency of the sample from a table in which the concentration of the pre-stored frequency-TDS standard solution is formulated, and the error of the TDS concentration according to the temperature of the sample detected by the sensor unit. Correct the TDS concentration of the sample by reflecting.

7 is a graph showing the frequency change characteristics according to the TDS concentration change of the TDS standard solution.

In order to investigate the TDS response characteristics of the portable TDS / salinity measuring device according to an embodiment of the present invention, the frequency change characteristic of the TDS concentration was investigated using a TDS standard solution (1 ppm to 999 ppm). 7 is the TDS concentration (ppm) of the standard solution, and the vertical axis represents frequency (Hz). As shown in FIG. 7, the frequency change according to the TDS concentration change was programmed after obtaining the most accurate equation through curve fitting. According to the equation, if the TDS is 500 ppm, the frequency is 500 Hz. Based on this, a table formulating the concentration of the frequency-TDS standard solution is prepared and used in the second calculation unit.

8 is a graph showing the precision between the measuring by repeating the measurement with a TDS / salinometer which is an embodiment of the present invention.

In order to investigate the accuracy of the measurement period by repeating the measurement of the TDS / salinometer which is an embodiment of the present invention, five measuring instruments were measured 10 times using a TDS standard solution (1 ppm to 999 ppm). 8 is the concentration (ppm) of the TDS standard solution, and the vertical axis is the measured value (ppm) of the TDS standard solution measured by the TDS / salin measuring device according to one embodiment of the present invention. As shown in FIG. 8, the deviation of the measured value was found to have a value within ± 3% of the maximum measured value (999ppm) as a whole, and also to maintain linearity.

FIG. 9 is a graph illustrating a measurement of TDS according to a temperature change with a TDS / salin measuring device according to an embodiment of the present invention.

9 is the concentration (ppm) of the TDS standard solution, and the vertical axis is the measured value (ppm) of the standard solution measured by the TDS / salin measuring device according to one embodiment of the present invention. In order to investigate the accuracy of the TDS measurement value according to the temperature change of the TDS / salter, the TDS standard solution (1ppm to 999ppm) was used for 10 times in the temperature range of 0 ° C to 40 ° C. As shown in FIG. 9, the deviation of the measured value was found to have a value within ± 3% of the maximum measured value (999 ppm) as a whole, and also to maintain linearity.

The keypad 150 includes a mode selection key and a hold (test) key. The mode selector and the hold (test) key can be selected by the user.

The control unit 155 sends the TDS concentration or salinity (salinity) and the temperature measurement value of the sample to the output unit according to the operation of the mode selection key. Immerse the electrode in the sample and hold the measured value automatically when the measured value is stabilized (measurement is completed) .If you want to measure the sample again, operate the hold (test) key to measure the TDS concentration, salinity and temperature of the sample.

Each time the mode selection key (preferably the MODE part shown in FIG. 10) is pressed, the TDS concentration, salinity concentration and temperature are selected. The control unit transmits the corresponding values to the output unit, preferably the LCD screen.

When the sample is stabilized and automatically held when measuring the sample, when the sample is to be measured again, the hold (test) key (preferably the TEST portion shown in FIG. 10) is measured.

An output unit, not shown, preferably an LCD screen, displays the measured value. In addition, a function for notifying measurement completion and a function for notifying battery replacement time may be further displayed.

10 is a view showing the appearance of the TDS / salinometer according to an embodiment of the present invention.

Portable TDS / Salinometers are intended for the immediate measurement of salinity and TDS contained in aqueous solutions in everyday life or on site. Therefore, small size and light weight, convenient to carry, easy to use, there is no problem to use with one hand. It is shaped like a rod in consideration of safety for users and devices from external shocks and heat.

11 is a diagram illustrating a circuit of a TDS / salin meter according to an embodiment of the present invention.

Microprocessor was used to make the product smaller and battery life was increased by using low power device with low power consumption. In addition, the battery usage is displayed so that the user can know the replacement time. The self-diagnosis function is added to the program for the user's convenience. The complicated operation is avoided and the comparison operation is used.

That is, two electrodes made of gold are connected to the circuit to measure the stable conductivity of the sample. From the frequency calculator, use the conductivity to find the frequency of the sample. The calculator is connected to a microprocessor with a program that calculates salinity and TDS in the sample. The signal processing program is designed to correct the salinity concentration and the TDS error according to the temperature, and is designed to output stable results regardless of the temperature change.

Also included in the output is an LCD panel that displays the salt concentration and TDS calculated by the microprocessor and a buzzer to inform the user that the measurement is complete. When the measured value is stabilized, the function is automatically held on the control part to make it convenient for the user to check the measured value.The low-power device with low power consumption increases the battery usage time and at the same time. It is designed to turn off the power automatically when it is not used for longer time.

An output unit, preferably an LCD screen, displays battery usage so that the user can know when to replace the battery, and is designed to selectively display salinity concentration, TDS concentration and temperature .

Looking at the circuit configuration, the two electrodes are connected to the connector of the frequency calculator, and the frequency calculator includes a feedback circuit composed of two transistors and a variable resistor between the input and output ports of the NAND gate to convert a part of the output signal into an input signal. Therefore, it is configured to strongly respond to the input signal measured by the electrode .

And functions such as constant voltage IC to supply constant voltage to circuit, measuring device switching part, stabilizer that does not overload the circuit when power on / off and power part equipped with power switch and LCD panel displaying salinity concentration, TDS, temperature It was configured as an output unit provided with a buzzer to inform the user that the measurement is completed as a sound.

12A and 12B are diagrams of a sampling aid according to an embodiment of the present invention. The sampling aid includes an opening 310, a holding part 320, and a sampling part 330.

The opening 310 is inserted with the electrode part of the meter, preferably the TDS / salter meter. Insertion degree is enough to measure the salinity concentration, TDS concentration and temperature of the electrode portion is sufficiently locked in the sample, the degree is determined by the holding portion 320 and the collecting portion groove (330a). The groove 330a of the collecting portion is formed so that the portion into which the measuring device is inserted is in close contact with the inside of the collecting portion.

The holding part 320 is connected to the opening and fixes one side of the inserted part to closely contact the inserted part to the inside of the collecting part. That is, one side of the inserted part of the measuring device is a collecting part 330 (preferably the groove 330a of the collecting part), and the other side of the inserted part of the measuring device is a holding part 320 connected to the opening (preferably In addition to the bent portion, it is possible to fix the measuring device by using an elastic material, so that the current can be stably flowed through the electrode and the salt concentration of the sample can be fixed. In addition, it will be possible to measure TDS concentration and temperature, and will prevent the meter from escaping from the sampling aid.

The sampling unit 330 is connected to the opening and holds a predetermined amount of the sample. When the sample is a high temperature it is difficult to measure the measurement by putting the measuring device directly in the sample, there was a problem that can be part of the body. However, the measurement after separating the sample in another container could be a problem such as the inconvenience of having to prepare another container separately, an error occurs by changing the sample temperature. Therefore, since the electrode is sufficiently submerged in the sample, a portion of the sample is collected, thereby reducing errors due to temperature changes, and preventing the risk of removing a part of the body. Sampling aids use materials that are stable (eg plastic, rubber, metal, etc.) without distortion or deformation even in hot samples.

Sampling aids can be combined with and separated from the sampler (preferably the sensing part).

As described above, according to the TDS / salinometer according to the present invention, not only the salt concentration but also TDS (Total Dissolved Solids) can be easily measured together. Changes in salinity and TDS in aqueous solution were analyzed by frequency change, and a low-power portable TDS / salt detector was developed using low-power devices with low power consumption. And the reproducibility, persistence and stability of the frequency change value according to the concentration change are very good.

In addition, it is possible to correct the error of the measured value according to temperature by formulating the frequency change according to the temperature change.

In addition, even when the sample is hot, salinity, TDS concentration and temperature can be measured simply and without risk by using a measuring aid (preferably the electrode part for sensing the sample) and a sampling aid that is easy to combine and separate. .

TDS / salinity measuring apparatus according to the present invention can be used in all fields to measure the ion concentration, preferably salt concentration, TDS concentration and temperature in the aqueous environment samples, such as industrial and household food, such as water environment, food and beverage manufacturing process.

Claims (7)

Two electrodes in contact with the sample; A circuit unit supplying current to the two terminals and having a predetermined resistance value and capacitance; A frequency calculator which calculates a frequency of the sample using a resistance value of the sample through which the current flows; A calculation unit for obtaining the ion concentration of the sample corresponding to the frequency of the sample from a table in which the ion concentration of the standard solution stored in advance is formulated; An output unit displaying ion concentration of the sample; And An opening inserted into the electrode portion, connected to the opening portion, a holding portion fixing one side of the inserted portion so as to be in close contact with the inside of the collecting portion, and connected to the opening portion, And a sampling aid including a collecting part for holding a predetermined amount of a sample. The method of claim 1, A sensor unit for sensing a temperature of a sample using a temperature sensor mounted on one of the electrodes; A correction unit positioned between the calculation unit and the output unit and correcting an ion concentration of a sample by reflecting an error of a concentration according to a temperature detected by the sensor unit; And And an output unit for displaying the corrected ion concentration of the sample and the temperature of the sample. Two electrodes in contact with the sample; A circuit unit supplying current to the two terminals and having a predetermined resistance value and capacitance; A frequency calculator which calculates a frequency of the sample using the resistance of the sample through which the current flows; A sensor unit for sensing a temperature of a sample using a temperature sensor mounted on one of the electrodes; The salinity concentration of the sample corresponding to the frequency of the sample is obtained from a table formulating the concentration of the pre-stored frequency-saline standard solution, and the salinity of the sample is corrected by reflecting the measurement error according to the temperature of the sample detected by the sensor unit. A first calculation unit to perform; The TDS concentration of the sample corresponding to the frequency of the sample is obtained from a table formulating the concentration of the pre-stored total TDS (Total Dissolved Solids) standard solution, and the measurement error according to the temperature of the sample detected by the sensor unit. A second calculator configured to correct the TDS concentration of the sample by reflecting the reflection; A keypad including a mode selection key and a hold (test) key; And A control unit which sends a TDS concentration, a salinity concentration, and a temperature of the corrected sample to an output unit according to the operation of the mode selection key, and displays a measured value on the output unit for a predetermined time during a hold (test) key operation; TDS / salinometer characterized in that it comprises a. The method of claim 3, The output unit TDS / salinity measuring unit further comprises a function for indicating the completion of the measurement, the function of notifying the battery replacement time. The method according to claim 3 or 4, An opening into which an electrode portion of the TDS / salmeter is inserted; A holding part connected to the opening and fixing one side of the inserted part to closely contact the inserted part to an inside of a collecting part; And And a sampling unit connected to the opening, the sampling unit having a predetermined amount of the sample. The method of claim 5, And the sampling unit includes a groove for guiding the inserted portion inside the collecting unit. As used in the measuring device of claim 1, Can be combined with and separated from the sampler, An opening into which a sample detecting portion of the sample measuring instrument is inserted; A holding part connected to the opening and fixing one side of the inserted part to closely contact the inserted part to an inside of a collecting part; And And a sampling part connected to the opening and holding a predetermined amount of the sample.