KR100629320B1 - Salt sensor of differential form and salt measurement device using it - Google Patents

Abstract

The present invention relates to a differential salinity sensor and a salinity measuring apparatus using the same, through a circuit in which four impedance (Z1, Z2, Z3, Z4) devices are connected in a lozenge and bridged opposite corners to a power supply branch and a detector branch, respectively. The standard seawater cylinder and the measured seawater cylinder are in the form of a differential bridge in an equilibrium state that satisfies the condition of Z1Z2 = Z3Z4 and the potential difference between the detector branch ends and no current flows when the power is supplied to the branch. After measuring the electrical conductivity of the standard seawater and the measured seawater by applying, characterized in that configured to measure the salinity of the measured seawater through the difference in the measured electrical conductivity.

According to the present invention, it is possible to perform accurate measurement while minimizing the influence of the surrounding environment by comparing the difference in electrical conductivity between standard seawater and measured seawater in the form of a differential bridge under the same temperature and pressure conditions.

Differential, salinity, conductivity, sensor, measurement, bridge structure

Description

SALT SENSOR OF DIFFERENTIAL FORM AND SALT MEASUREMENT DEVICE USING IT}             

1 is a general bridge circuit diagram,

2 is an equivalent circuit diagram of a differential salinity sensor to which a bridge structure is applied according to the present invention;

3 is a schematic view of a measuring seawater cylinder according to the present invention;

4A and 4B are schematic views of the upper and lower stoppers of the measuring seawater cylinder;

5 is a schematic view of a standard seawater cylinder according to the present invention;

6A and 6B are schematic views of upper and lower stoppers of standard seawater cylinders,

7 is an external view of a salt measuring device according to the present invention.

* Explanation of symbols for main parts of the drawings

Z1, Z2, Z3, Z4: Impedance P, Q, R, S: Impedance

C1, C2, C3, C4: Capacitance 10: AC power terminal

20: measuring seawater cylinder 21: upper stopper

22: measuring seawater inlet space 23: lower stopper

24: Measurement seawater outflow opening 30: Standard seawater cylinder

31: Upper Stopper 32: Standard Seawater Storage

33: lower stopper 50: salinity measuring device

51: housing

51-1: Cylindrical groove for standard seawater cylinder

51-2: Cylindrical Groove for Measuring Seawater Cylinder

51-3: Opening port for measuring seawater cylinder

The present invention relates to a differential salinity sensor, and more particularly, to a differential salinity sensor for measuring salinity of a measured seawater after comparing the electrical conductivity of standard seawater and measured seawater by applying a differential bridge type, and a salinity measuring apparatus using the same.

The salinity of the ocean can be calculated by measuring electrical conductivity. Indirect measurement method is used to measure electrical conductivity (C), water temperature (T), and water pressure (D), and then calculate them by the relationship between salinity. In this case, the electrical conductivity may change depending on the water temperature and the water pressure, and the measurement system may also be affected by the surrounding environment.

However, in order to accurately measure the salinity by such an indirect measuring method, it is not only inconvenient to frequently calibrate, but also has a problem that it is difficult to know the absolute accuracy of the measured value. In addition, there is a problem that the CTD which is a measuring device to which such a measuring method is applied is quite expensive.

Therefore, the present invention has been made to solve the above problems, and compares the difference in electrical conductivity between standard seawater and measured seawater in the form of a differential bridge under the same conditions, and directly measures the salinity of the seawater, while minimizing the influence of the surrounding environment. Yet another object of the present invention is to provide a differential salinity sensor and a salinity measuring device using the same.

In order to achieve the above object, a differential salinity sensor according to the present invention comprises a circuit in which four impedance (Z1, Z2, Z3, Z4) elements are connected in a lozenge and bridged opposite corners to a power supply branch and a detector branch, respectively. The standard seawater cylinder and the measured seawater cylinder are differentially bridged in a bridge structure that satisfies the condition of Z1Z2 = Z3Z4 when the power is supplied to the power supply branch and the condition that the potential difference between the detector branch becomes zero and no current flows. After measuring the electrical conductivity of the standard seawater and the measured seawater by applying to, characterized in that it is configured to measure the salinity of the measured seawater through the difference in the measured electrical conductivity.

At this time, the standard seawater cylinder has a top and bottom stopper each formed with an electrode plate insulated with an insulating plate, but the vertical movement of the top stopper is to be adjusted so that the pressure inside the cylinder generated by the sea water is stored in the same manner as the external water pressure It is preferable that the measuring seawater cylinder is provided with upper and lower stoppers each having an electrode plate insulated with an insulating plate, and opens a part of the cylinder wall to allow the inflow and outflow of seawater.

On the other hand, in the salinity measuring apparatus using the differential salinity sensor according to the present invention, a power supply of a circuit in which four impedance (Z1, Z2, Z3, Z4) elements are connected in a lozenge and bridged opposite corners to a power supply branch and a detector branch, respectively. Standard seawater cylinder and measuring seawater cylinder are applied in the form of differential bridge in a balanced structure that satisfies the condition of Z1Z2 = Z3Z4 when the power is applied to the branch and the potential difference between the detector branch is zero and no current flows. A differential salinity sensor for measuring salinity of measured seawater by measuring the electrical conductivity of standard seawater and measured seawater and then measuring the electrical conductivity; And a housing accommodating the differential salinity sensor and a power supply means, and having a cylindrical groove formed as a cylinder of the differential salinity sensor.

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

First, referring to FIG. 1, a bridge structure applied to measuring absolute values of a measurement material by comparing characteristics of a standard material and a measurement material will be described.

As shown in Fig. 1, the bridge circuit connects four impedance (Z1, Z2, Z3, Z4) elements in a rhombic shape and bridges opposite corners to a power supply branch and a detector branch, respectively. At this time, when the reference voltage is applied to the A and B terminals, the potential difference between the conditions of Z1Z2 = Z3Z4 and the C and D terminals becomes zero, thereby achieving an equilibrium state that satisfies the condition that no current flows.

If the measurement material is applied at the Z3 position and the reference material is applied at the Z2 position, the reference voltage is applied, and the voltage for the measurement material is output to the C terminal and the voltage for the standard material is output to the D terminal. The absolute value of can be measured. At this time, since the bridge structure is symmetrical, the potential difference between C and D becomes zero when the characteristic of the measurement material is the same as that of the standard material.

In the above description, the impedance is compared as an example, but electrical characteristics such as capacitance or inductance may also be compared.

2 is an equivalent circuit diagram of a differential salinity sensor to which a bridge structure is applied according to the present invention. That is, in order to measure the salinity of the measured seawater after comparing the electrical conductivity of the measured seawater and the standard seawater to the bridge structure, one side applies the measurement seawater cylinder 20 and the other side applies the standard seawater cylinder 30. will be.

As shown in FIG. 2, the measuring seawater cylinder 20 has an equivalent circuit in which C1, R, and C2 are connected in series according to the action of an electrode plate, an insulating plate, seawater, an insulating plate, and an electrode plate arranged in a line. The standard seawater cylinder 30 may also be represented as an equivalent circuit in which C3, Q, and C4 are connected in series according to the action of electrode plates, insulating plates, seawater, insulating plates, and electrode plates arranged in a line. have. This will be described in more detail with reference to FIGS. 3 and 4.

The reason for applying the AC power through the AC power source 10 is to obtain the potential difference through the capacitor. Therefore, the AC power is applied to compare the electrical conductivity proportional to the potential difference generated through the circuit consisting of C1, R, C2 and the circuit consisting of C3, Q, C4.

By changing the P value, C1 and C3 are the same, and C2 and C4 can form the same symmetrical structure. Looking at the adjustment method, the standard seawater is inserted into the measuring seawater cylinder 20, and the P value is corrected so that the potential difference between C and D becomes zero.

On the other hand, the accuracy of the salinity sensor increases as the capacitance of C1, C2, C3, C4 is larger, and the cylinder length is longer. In addition, when the frequency of the AC power source 10 is high, the AC impedance of C1, C2, C3, C4 becomes smaller than the impedance value for seawater, so the accuracy is increased.

3 is a schematic view of a measuring seawater cylinder according to the present invention, and FIGS. 4A and 4B show schematic diagrams of upper and lower stoppers of the measuring seawater cylinder.

As shown in FIG. 3, the measurement seawater cylinder 20 includes upper and lower stoppers 21 and 23, a measurement seawater inflow space 22, and a measurement seawater inflow and outflow opening 24. As such, the seawater cylinder 20 may freely flow in or out of the seawater.

The upper stopper 21 is composed of a fixing thread 21-1, an O-ring 21-2, an electrode plate 21-3, and an insulating plate 21-4, as shown in FIG. 4A. The lower plug 23 also includes a fixing screw thread 23-1, an O-ring 23-2, an electrode plate 23-3, and an insulating plate 23-4, as shown in FIG. 4B. At this time, one or more O-rings (21-2, 23-2) may be used as necessary.

 The fixing threads 21-1 and 23-1 are for fixing the upper and lower stoppers 21 and 23 to the cylinder 20, and the O-rings 21-2 and 23-2 are for waterproof purposes, that is, The sea water flowing into the cylinder 20 is prevented from flowing out.

In addition, the electrode plates 21-3 and 23-3 are terminals to which AC power is applied from the outside in order to measure the electrical conductivity of seawater, and the insulating plates 21-4 and 23-4 are electrode plates 21-3, respectively. 23-3) is prevented from directly contacting the sea water to prevent corrosion of the electrode plates 21-3 and 23-3. In addition, the measurement seawater inflow opening 24 is used as a passage through which the measurement seawater can freely flow in or out.

On the other hand, when power is applied to the electrode plates 21-3 and 23-3 of the cylinder 20 having such a shape, the insulating plates 21-4 and 23-4 are introduced into the measured seawater and the electrode plates 21-3, By acting as a capacitor between 23-3) to form an equivalent circuit of the type C1, R, C2 connected in series as shown in FIG.

5 is a schematic view of a standard seawater cylinder according to the present invention, and FIGS. 6A and 6B show schematic views of upper and lower stoppers of the standard seawater cylinder.

The standard seawater cylinder 30 is composed of upper and lower stoppers 31 and 33 and a standard seawater storage space 32, as shown in FIG. As such, the standard seawater cylinder 30 stores standard seawater in an enclosed space.

The upper plug 31 is composed of an O-ring 31-2, an electrode plate 31-3, and an insulating plate 31-4, as shown in FIG. 6A. As such, the upper stopper 31 is freely moved up and down so that the pressure inside the cylinder 30 generated by storing the sea water can be adjusted to be equal to the external water pressure. That is, it can move freely up and down according to the external pressure.

The lower plug 33 is composed of a fixing thread 33-1, an O-ring 33-2, an electrode plate 33-3, and an insulating plate 33-4, as shown in FIG. 6B. In this way, the lower cap 33 is fixed to the cylinder 30 by fixing threads 33-1.

On the other hand, when power is applied to the electrode plates 31-3 and 33-3 of the standard seawater cylinder 30 having such a shape, the insulating plates 31-4 and 33-4 are stored in the standard seawater and electrode plate 31-3. By acting as a capacitor between the and, 33-3) to form an equivalent circuit of the type C3, Q, C4 connected in series as shown in FIG.

7 is an external view of the salinity measuring apparatus according to the present invention, the salinity measuring apparatus 50 measures the electrical conductivity of the standard seawater and the measured seawater by applying a standard seawater cylinder and a measuring seawater cylinder in the form of a differential bridge, and then Differential salinity sensor configured to measure salinity of the measured seawater through the difference in electrical conductivity, a power supply means for supplying AC power to the differential salinity sensor, and a housing for accommodating the differential salinity sensor and power supply means ( 51).

In order to implement the present invention preferably, the shape of the housing 51 is a cylindrical groove 51-1 for use as a standard seawater cylinder of a differential salinity sensor as shown in FIG. 7 and for use as a measuring seawater cylinder. Cylindrical grooves 51-2 are formed separately.

At this time, the salinity measuring device 50 is a form that can be used directly into the seawater of the salinity measurement target, the cylindrical groove (51-2) for use as a measuring seawater cylinder can be made freely inflow and outflow of external seawater An opening 51-3 is formed. Acetal materials may be used as the material of the housing 51.

As described above, the differential salinity sensor and the salinity measuring apparatus using the same compare the difference in electrical conductivity between standard seawater and measured seawater in the form of a differential bridge under the same temperature and pressure conditions, and then measure the salinity of the measured seawater. Accurate measurement can be performed while minimizing

On the other hand, the present invention is not limited to the above-described embodiment and can be carried out variously modified by those skilled in the art within the scope not departing from the technical spirit of the present invention can measure the salinity in a more efficient manner.

Claims (3)

In the sensor for measuring salinity, Through a circuit in which four impedance (Z1, Z2, Z3, Z4) elements are connected in a lozenge and the opposite corners are bridged into a power supply branch and a detector branch, respectively, the condition of Z1Z2 = Z3Z4 and detector branch when power is applied to the power supply branch. In a bridge structure that forms an equilibrium state that satisfies the condition that the potential difference of the stage becomes zero and no current flows, Standard seawater cylinders and measuring seawater cylinders are applied in the form of differential bridges to measure the electrical conductivity of standard seawater and measured seawater, and the salinity of the seawater can be measured by the difference in the measured electrical conductivity. The standard seawater cylinder is provided with an upper and lower stoppers, each formed with an electrode plate insulated with an insulating plate, the upper stopper is movable up and down, The measuring seawater cylinder is provided with a top and bottom stopper, each formed with an electrode plate insulated with an insulating plate, a differential salinity sensor, characterized in that a portion of the cylinder wall is open to the flow of seawater. delete In the device for measuring salinity, Claim 1 differential salinity sensor; Power supply means for supplying AC power to said differential salinity sensor; And The salinity measuring device using the differential salinity sensor, characterized in that the housing for receiving the differential salinity sensor and the power supply means formed a cylindrical groove that can be used as a cylinder of the differential salinity sensor.

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