KR102124215B1 - Conductivity meter, and method for correcting measurement, setting initial state and calibration of conductivity meter - Google Patents

Abstract

In the present invention, by accurately obtaining the temperature of the annular magnetic body, the measurement conductivity obtained by the measurement unit is corrected for each temperature of the annular magnetic body, and the electrical conductivity is measured with high accuracy. The primary coil 31 and the secondary coil 32 ), the primary-side magnetic material 21 on which the primary coil 31 is wound, and the secondary-side magnetic material 22 on which the secondary coil is wound, and a power supply unit 5 for applying an alternating voltage to the primary coil 31. , In the conductivity measuring system 100 having a measuring unit 6 for measuring conductivity from the induced current generated in the secondary coil 32, at least one of the primary magnetic body 21 or the secondary magnetic body 22 And a temperature sensor 45 for measuring the temperature directly or indirectly.

Description

CONDUCTIVITY METER, AND METHOD FOR CORRECTING MEASUREMENT, SETTING INITIAL STATE AND CALIBRATION OF CONDUCTIVITY METER}

The present invention is a conductivity measuring system for measuring the conductivity of an object to be measured from an induced current generated in the secondary coil through a measurement object when a predetermined alternating voltage is applied to the primary coil and a method for correcting the measured value to be.

As a conductivity measuring system of this kind, an annular tube member to which a measurement object is introduced, an annular magnetic body through which the annular tube member passes, and a primary magnetic flux ring wound around the annular magnetic body A primary coil forming a secondary coil and a secondary coil forming a secondary magnetic flux ring, a power supply unit for applying a predetermined AC voltage to the primary coil, and measuring the induced current of the secondary coil generated by the application of the AC voltage, , It is known to have a measuring unit that calculates the conductivity of a measurement object based on the induced current.

By the way, it is known that the magnetic permeability of a cyclic magnetic body changes with the temperature of the cyclic magnetic body. For example, Patent Document 1 discloses that a change in the magnetic permeability according to a change in the ambient temperature of the annular magnetic material limits the detection accuracy of the conductivity.

However, patent documents such as measuring the temperature of the annular magnetic material are not noticeable. For example, in Patent Document 2, a platinum resistance for temperature detection is provided in the vicinity of the annular magnetic body, but this platinum resistance is covered with a resin, and the heat transfer from the annular magnetic body is poor. It is not possible to measure temperature.

[Patent Document 1] Japanese Patent Application Publication No. 10-153564 [Patent Document 2] Japanese Patent Publication No. 2000-131286

The present invention has been made in order to solve the above problems, and its main goal is to accurately obtain the temperature of the annular magnetic body and measure the conductivity with high precision.

The conductivity measuring system according to the present invention forms a primary magnetic flux ring, and a primary coil disposed such that a measurement object forming a closed loop penetrates the primary magnetic flux ring, and a secondary magnetic flux ring, so that the measurement object is A secondary coil disposed to penetrate the secondary magnetic flux ring, a primary annular magnetic body on which the primary coil is wound, a secondary annular magnetic body on which the secondary coil is wound, and a predetermined alternating voltage to the primary coil In the conductivity measuring system having a power supply unit to be applied, and a measuring unit for measuring the conductivity of the measurement object from the induced current generated in the secondary coil, the temperature of at least one of the primary annular magnetic material or the secondary annular magnetic material is It is characterized by having a temperature sensor that measures directly or indirectly.

In such a case, since the temperature sensor directly or indirectly measures the temperature of the annular magnetic body, the temperature by the temperature sensor indicates the correct temperature of the annular magnetic body, and the measured conductivity measured by the measuring unit is corrected using the temperature. By doing so, the electrical conductivity can be accurately determined.

As a specific embodiment of the temperature sensor, the temperature sensor is provided on at least one of the primary-side accommodating member accommodating the primary-side annular magnetic body or the secondary-side accommodating member accommodating the secondary-side annular magnetic body, and the temperature of the accommodating member And measuring.

In order to improve the heat transfer from the annular magnetic body to the temperature sensor and to indirectly measure the temperature of the annular magnetic body, the temperature by the temperature sensor is responsive to exhibit the correct temperature of the annular magnetic body, the primary accommodating member and the 2 It is preferable that the vehicle-side accommodating member is made of metal.

As a specific embodiment for correcting the measurement conductivity from the temperature of the housing member, a temperature characteristic data storage unit that stores temperature characteristic data that is data representing the relationship between the temperature of the annular magnetic body and the measurement conductivity, and the temperature characteristic data and the It is preferable to have a correction unit that corrects the measurement conductivity measured by the measurement unit based on the temperature of the housing member.

In order for the measurement temperature by the more responsive temperature sensor to indicate the temperature of the annular magnetic body, the accommodating member has an annular accommodating space for accommodating the annular magnetic material, and the annular magnetic material in which the coil is wound wraps the accommodating space. It is preferable that it is sandwiched between the outer cylinder part and the inner cylinder part to be formed and is contained without rattling.

Moreover, it is preferable that each said accommodation member is provided in contact or in close proximity, and it is made of the same material and has the same shape with each other.

Here, the proximity refers to a positional relationship in which each of the accommodating members is disposed so that the ambient temperature of each of the primary accommodating member and the secondary accommodating member is the same or different temperatures do not substantially affect the measurement by a slight difference.

With this configuration, since the temperature of the housing member of each of the housing members is the same, a temperature sensor may be provided on either the primary storage member or the secondary storage member.

As a specific embodiment in which the effect of the present invention becomes particularly remarkable, the measurement target is a liquid, and further includes an annular tube member forming an annular flow path through which the liquid flows, and the inner circumferential surface of the receiving member and the outer circumferential surface of the annular tube member. It may be mentioned that the receiving member is mounted without agitation in contact with this.

As described above, when the inner peripheral surface of the receiving member and the outer peripheral surface of the annular tube member are in contact with each other in order to mount the receiving member without rattling, the annular magnetic body is susceptible to influence by the temperature of the measurement object, but according to the present invention, the receiving member Since the temperature of the responsively represents the temperature of the annular magnetic body with good responsiveness, it is possible to accurately obtain the conductivity by considering the temperature of the housing member as the temperature of the annular magnetic body and correcting the measured conductivity.

In the method for correcting the measurement value of the conductivity measuring system according to the present invention, a primary side magnetic flux ring is formed to form a primary loop and a secondary side magnetic flux ring is formed so that a measurement object forming a closed loop passes through the primary side magnetic flux ring, The secondary coil provided so that the measurement object passes through the secondary magnetic flux ring, the primary annular magnetic body on which the primary coil is wound, and the secondary annular magnetic body on which the secondary coil is wound, and the primary coil are predetermined. A method for calibrating a measured value of a conductivity measuring system comprising a power supply unit for applying an alternating voltage and a measurement unit for measuring the conductivity of the measurement object from the induced current generated in the secondary coil, wherein the primary ring-shaped magnetic body or the secondary ring-shaped magnetic body It is characterized by directly or indirectly measuring the temperature of at least one of them.

If it is such a thing, the temperature of a cyclic magnetic body is measured directly or indirectly, and the measurement conductivity can be corrected using the correct temperature of the cyclic magnetic body, and it becomes possible to obtain a conductivity accurately.

In order to obtain an accurate temperature of the cyclic magnetic body with good responsiveness, the temperature of at least one of a metal primary side receiving member for receiving the primary side annular magnetic body or a metal secondary side receiving member for accommodating the secondary side magnetic body is measured. , Recording temperature characteristic data which is data representing the relationship between the temperature of the annular magnetic body and the measured conductivity, and considering the temperature of the accommodating member as the temperature of the annular magnetic body, based on the temperature of the accommodating member and the temperature characteristic data , It is preferable to correct the measurement conductivity measured by the measuring unit.

In addition, as the conductivity measurement system, for example, as shown in Fig. 6, the annular tube member into which the liquid sample to be measured is introduced, and attached to the annular tube member through a Troidal core, the primary side magnetic flux ring A primary coil forming a secondary coil and a secondary coil forming a secondary magnetic flux ring, a power supply unit for applying a predetermined alternating voltage to the primary coil, and an output induction which is an induction current of the secondary coil generated by application of the alternating voltage It is known to have a measuring unit that measures a current and calculates the conductivity of a liquid sample based on the output induced current.

By the way, in this type of conductivity measuring system, changes in the measurement sensitivity due to changes in the characteristics of the troder core, variations in the power supply voltage, etc., adversely affect the measurement accuracy, making it impossible to measure the conductivity accurately.

Thus, for example, the conductivity measuring system described in Japanese Patent Application Laid-Open No. 4-361168 is equipped with a fixed resistance circuit that can be opened and closed with a constant resistance value (i.e., constant conductivity) in the primary coil and the secondary coil. During the measurement, the difference between the measurement conductivity in the open state and the measurement conductivity in the closed state is configured to correct the measurement sensitivity so as to match the effective conductivity of this fixed resistance circuit, and ensure measurement accuracy. .

However, when the conductivity of the object to be measured is low, higher measurement accuracy is required because various noises greatly affect the output induced current obtained by the measurement unit, but in the conventional conductivity measurement system, the measurement accuracy is improved. There is a problem that you cannot.

As the noise affecting the output induced current, for example, two types as shown below are mentioned.

The first noise is propagated to the secondary coil as a current flows through a circuit or a circuit on the substrate constituting the conductivity measuring system to generate a noise current, and the output induced current is generated in the secondary coil through the measurement object. These noise currents are added to or subtracted from each other to the induced current (hereinafter also referred to as signal current).

That is, this noise current, as illustrated in FIGS. 7 and 8, has directionality and is induced to the secondary coil by flowing current through a noise loop that forms a closed loop through the primary magnetic flux ring and the secondary magnetic flux ring. It can be considered to be electrically equivalent to the first noise current, and this directionality is determined by the direction (hereinafter, referred to as loop direction) through which the noise loop penetrates the magnetic flux ring.

Further, in a conductivity measuring system in which wiring, circuits on the board, and the like have the same configuration, the loop direction of this noise loop and the magnitude of the current flowing through the noise loop by the application of an alternating voltage are the same.

And if the measurement object has a conductivity less than or equal to a certain level, the ratio of the signal current to the first noise current (S/N ratio) becomes small, and it is impossible to guarantee a predetermined measurement accuracy.

In addition to this, if the loop direction of the above-described noise loop is not known, it is not possible to determine whether the first noise current is added to or subtracted from the signal current, so it is not even known whether the measured conductivity is less than or equal to the effective value.

The second noise has no directionality caused by heat or vibration.

The output induction current can be obtained by converting the current flowing through the secondary coil into a voltage signal in the measurement unit, and then rectifying or smoothing the signal to direct current to the signal. Are overlaid on.

In the region where the effective conductivity of the object to be measured is less than or equal to a certain level, the influence of the second noise increases, and a nonlinear region in which the relationship between the output induced current obtained by rectification and smoothing treatment and the effective conductivity of the object to be measured becomes nonlinear. It is formed, and it becomes difficult to accurately obtain the effective conductivity of the measurement object based on the output induced current in this region.

As described above, when the conductivity of the object to be measured is low, various noises greatly affect the output induced current, and accordingly, it is difficult to accurately obtain the conductivity.

The present invention aims to make it possible to measure the conductivity with high precision even if it is a measurement target with a lower conductivity. That is, in the initial state setting method of the conductivity measuring system according to the present invention, a primary coil forming a primary magnetic flux ring and a secondary coil forming a secondary magnetic flux ring, and applying a predetermined alternating voltage to the primary coil Conductivity of the measurement object from an output induction current, which is an induction current generated in the secondary coil, in a state in which the primary coil and the secondary coil are disposed so that the measurement object forming a closed loop passes through their magnetic flux rings. A method for setting an initial state of a conductivity measuring system having a measuring unit for measuring, comprising: an annular circuit passing through the primary magnetic flux ring and the secondary magnetic flux ring, an impedance variable element that changes the impedance of the annular circuit, and A step of providing an annular circuit having an inversion mechanism for reversing the loop direction that is a through direction of the annular circuit with respect to the magnetic flux ring, and a step of setting the loop direction of the annular circuit by the inversion mechanism; With, when the loop direction changes the impedance of the annular circuit by the impedance variable element by applying a predetermined alternating voltage to the primary coil, the output induced current decreases according to the change in impedance. It is characterized in that it is the direction in which the smallest point (極小点) that changes from) to augmentation appears.

In addition, in the loop direction of the annular circuit referred to herein, in a state in which a predetermined alternating voltage is applied to the primary coil, the current induced in the annular circuit and the current induced in the measurement object forming the closed loop are used for the secondary magnetic flux ring. In the case of the same direction when passing through, the reverse loop direction is the case where the current induced in the loop and the current induced in the measurement object forming the closed loop are reversed when passing through the secondary magnetic flux ring. Is done.

In this case, since the annular circuit penetrates the primary-side magnetic flux ring and the secondary-side magnetic flux ring, similarly to a noise loop, a predetermined alternating voltage is applied to the primary coil in a state where the measurement object is not mounted to improve the impedance of the annular circuit. By confirming the change in the output induced current when changed, the direction of the current flowing through the noise loop, that is, the loop direction of the noise loop can be grasped.

Thereby, the loop direction of the annular circuit is set so that the current induced in the annular circuit becomes a direction to cancel the current flowing in the noise loop when passing through the secondary magnetic flux ring, and the The impact can be minimal.

In order to measure more accurately, the impedance of the value smaller than the impedance at the smallest point is variable, so that the impedance is adjusted to be the maximum impedance among impedances in which the relationship with the output induced current obtained by the measuring unit is approximately linear. It is desirable to adjust the device.

By setting the initial state in this way, since the initial state before measurement can be set to avoid a nonlinear region in which the relationship between the output induced current and the effective conductivity of the measurement object becomes nonlinear due to the influence of the second noise, the measurement target of the lower conductivity Even in this case, it becomes possible to measure the conductivity with high precision.

In addition, as a result of avoiding the influence of the second noise, the output induced current when the effective conductivity of the measurement object is zero is minimized, so that the measurable range up to the measurement upper limit of the output induced current can be widened, and the measurement range is improved. Widens.

It is possible to easily invert the loop direction of the annular circuit, and to change the impedance of the annular circuit with one impedance variable element, even if the loop direction is set to any forward or reverse direction, the annular circuit is provided with the primary magnetic flux ring. A primary side wiring passing through and a secondary side wiring passing through the secondary magnetic flux ring are further provided, wherein the reversing mechanism has one end and the other end of the primary side wiring respectively at one end and the other end of the secondary side wiring. And a switch for switching a forward loop connection state in a connected state, and a reverse loop connection state in which one end and the other end of the primary-side wiring are connected to the other end and one end of the secondary-side wiring, respectively. , It is preferable to be provided on the primary side wiring or on the secondary side wiring.

As a specific example of the impedance variable element, there is a variable resistance element that changes the resistance value according to the position of the movable contact.

The conductivity measuring system according to the present invention includes a primary coil forming a primary-side magnetic flux ring and a secondary coil forming a secondary-side magnetic flux ring, a power supply unit for applying a predetermined AC voltage to the primary coil, and the primary coil And in a state in which the secondary coils are disposed so that the measurement objects forming the closed loop pass through their magnetic flux rings, the measurement unit measures the conductivity of the measurement object from the output induced current generated in the secondary coil. In the present invention, an annular circuit having a constant impedance mounted to penetrate the primary magnetic flux ring and the secondary magnetic flux ring is provided, and the inductive circuit generated by the annular circuit generates an additional induced current, which is an induced current in the secondary coil, during measurement. It is characterized by being.

In such a case, by generating an additional induced current at the time of measurement, so that the influence of the first noise and the second noise on the output induced current is minimized, it is possible to measure the conductivity with high precision even when the object is measured with a lower conductivity. Becomes

In order to cancel the current flowing in the noise loop when the current induced in the annular circuit passes through the secondary magnetic flux ring, the output when the conductivity of the measurement object is increased from zero in the state where the annular circuit is separated. When the induced current increases monotonically, the loop direction, which is a through-direction to the magnetic flux ring of the annular circuit, is set so that, by mounting the annular circuit, the output induced current decreases compared to the state in which the annular circuit is separated. It is preferred.

In addition, when the output induced current when the conductivity of the measurement object is increased from zero in the state where the annular circuit is separated, when the smallest point where the output induced current changes from decrease to increase, by mounting the annular circuit, the smallest point disappears It is preferable that the loop direction of the annular circuit, which is a through direction with respect to the magnetic flux ring, is set.

For more accurate measurement, the output induced current and the annular circuit at a minimum point at which the output induced current when the impedance of the annular circuit increases from 0 to the increase in conductivity of the measurement object are reduced to increased. It is preferable that the output induced current in the mounted state is an impedance having a value smaller than the matched impedance, and that the relationship between the output induced current and the conductivity of the measurement object is approximately linear, which is approximately the maximum impedance.

By setting the initial state in this way, as a result of avoiding a nonlinear region in which the relationship between the output induced current and the effective conductivity of the measurement object becomes nonlinear under the influence of the second noise, the output induced current when the effective conductivity of the measurement object is zero is minimal. Therefore, the measurable range up to the measurement upper limit of the output induced current can be widened, and the measurement range is widened.

In addition, the electrical conductivity is measured in various fields, for example, in order to obtain the concentration of salt or acid or alkali to be measured.

As a conductivity measurement system for this purpose, as shown in FIG. 15, for example, an annular tube member into which a liquid sample to be measured is introduced, a primary coil and a secondary coil mounted to the annular tube member through a trojan core, It has a power supply unit that applies a predetermined alternating voltage to the primary coil, and a measuring circuit that measures the induced current of the secondary coil generated by the application of the alternating voltage and calculates the conductivity of the liquid sample based on the measured induced current. It is known.

By the way, in this type of conductivity measuring system, since the measurement sensitivity changes due to a change in the characteristics of the troder core, a change in the amplification factor of the measurement circuit, or a change in the power supply voltage, periodically or every time (before or after measurement) After), it is necessary to correct the measurement sensitivity, that is, the ratio of the change in the measured value to the unit change in the effective conductivity.

Thus, conventionally, for example, a calibration annular circuit having a known resistance value (that is, known conductivity) is provided in parallel to the annular tube member so as to penetrate through each of the Troider cores. Then, the measurement sensitivity is corrected by measuring the conductivity in the state where the annular circuit for calibration is attached, and comparing the measured conductivity with the effective conductivity (that is, the conductivity known as the known annular circuit for calibration).

For example, the conductivity measuring system described in the publication of the publication No. 38-5072 has two resistance elements of known values with different calibration annular circuits, and by selecting which resistance element as a switch, the It is configured to switch resistance (ie conductivity). Then, at the time of calibration, the conductivity when each resistance element is selected is measured, and the amplification factor of the measurement circuit and the applied voltage by the power supply unit are measured so that the difference in the measured conductivity matches the difference in effective conductivity by each resistance element. Adjust your back.

In addition, the conductivity measuring system described in Japanese Patent Application Laid-Open No. 4-361168 is provided with an opening/closing switch for switching the annular circuit for calibration to an open state and a closed state. At the time of calibration, as in Patent Document 1, the amplification factor and power supply section of the measurement circuit are similar to those in Patent Document 1 so that the difference between the measurement conductivity in the open state and the measurement conductivity in the closed state coincides with the effective conductivity of this annular circuit for calibration. Adjust the applied voltage and so on. In addition, it is to cancel the influence of the offset by measuring the conductivity in the open state and taking the difference from the conductivity in the closed state, and by this configuration, it is possible to correct even in a state in which a liquid sample is placed in the annular member. .

However, in the conductivity measuring system, when a range switching mechanism is provided to switch a plurality of measurement ranges in order to increase the measurement precision or increase the measurement range, the conventional configuration described above can only calibrate one measurement range. There is a problem that the measurement accuracy in the measurement range cannot be guaranteed. Moreover, the measurement sensitivity cannot be limited to necessarily change linearly, and in such a case, there is also a problem that the conventional configuration cannot accurately calibrate.

An object of the present invention is to increase the measurement precision in a conductivity measurement system or to secure the measurement precision while attempting to widen the measurement range. The conductivity measuring system according to the present invention includes a primary coil forming a primary-side magnetic flux ring and a secondary coil forming a secondary-side magnetic flux ring, a power supply unit for applying a predetermined AC voltage to the primary coil, and the primary coil And a measurement unit that measures the conductivity of the measurement object from the induced current generated in the secondary coil when the secondary coil is mounted on their magnetic flux ring so that the measurement object forming the closed loop penetrates, and the measurement by the measurement unit. In a conductivity measuring system having a range switching unit for switching a range, an impedance circuit having a predetermined impedance passing through the primary magnetic flux ring and the secondary magnetic flux ring, and the impedance circuit is closed or open circuit ( It is characterized in that a plurality of circuits for correcting the sensitivity for correcting the measurement sensitivity by the measuring unit are provided so as to be switched for each measurement range, provided with an open/close switch for switching to any of the states.

In addition, the measurement sensitivity mentioned here is the ratio of the change of the measurement conductivity-related value, such as a current value or a voltage value, for calculating a measurement conductivity or a measurement conductivity with respect to the change of the effective conductivity of a measurement object.

In this case, since a plurality of circuits for correcting the sensitivity for correcting the measurement sensitivity by the measurement unit are provided to be switched in correspondence with each measurement range, it is possible to accurately calibrate the measurement sensitivity for each measurement range, thereby improving measurement accuracy. Alternatively, the measurement accuracy can be guaranteed while widening the measurement range.

To automate the calibration of the measurement sensitivity in each measurement range, and to improve the workability, the change in the conductivity or the conductivity-related value by the measurement unit when the sensitivity calibration circuit is switched between a closed-loop state and an open-loop state. Based on this, the measurement sensitivity calculation unit calculates the measurement sensitivity, the reference sensitivity storage unit that stores the reference sensitivity, which is the reference measurement sensitivity, for each measurement range, and the measurement sensitivity of each measurement range obtained by the measurement sensitivity calculation unit. , It is preferable that a calibration unit for calibrating to a corresponding reference sensitivity stored in the reference sensitivity storage unit is provided.

Even in the case where the measurement sensitivity changes in a nonlinear manner, in order to enable accurate sensitivity calibration, it is preferable that the plurality of circuits for sensitivity calibration are configured to be closed at the same time.

When configured in this way, a plurality of sensitivity calibration circuits in a closed-loop state can be regarded as one sensitivity calibration circuit having a composite impedance obtained by synthesizing each impedance, and correspond to this sensitivity calibration circuit and each measurement range. By performing a sensitivity correction using a circuit for sensitivity calibration that is switched over, high-precision sensitivity calibration is possible even when the measurement sensitivity changes nonlinearly.

In addition, by simultaneously setting a plurality of sensitivity calibration circuits in a closed-circuit state, a sensitivity calibration circuit having a synthetic impedance can be used at the time of calibration, so that an impedance circuit smaller than the number of measurement ranges can be used to calibrate the sensitivity in each measurement range. Becomes

In order to allow the user to recognize that the sensitivity correction circuit cannot exceed the upper limit of the measurement of the set measurement range by making the circuit for the sensitivity calibration closed, the sensitivity calibration circuit is closed. It is preferable to further include a warning section for outputting a warning signal when the conductivity by the measurement section exceeds the upper limit of measurement of the measurement range.

In order to reliably perform sensitivity calibration, it is preferable that the impedance of the impedance circuit is different for each measurement range.

As a specific configuration of the impedance circuit, there is a configuration in which the impedance circuit includes an impedance element having a predetermined impedance for each measurement range.

A specific example of the impedance element is a resistor having a known resistance value.

In addition, the calibration method according to the present invention includes a primary coil forming a primary-side magnetic flux ring and a secondary coil forming a secondary-side magnetic flux ring, a power supply unit for applying a predetermined AC voltage to the primary coil, and the 1 When a secondary coil and a secondary coil are attached to their magnetic flux rings so that a measurement object forming a closed loop penetrates, the measurement unit measures the conductivity of the measurement object from the induced current generated in the secondary coil, and the measurement unit A calibration method of a conductivity measuring system having a range switching unit for switching the measurement range by, comprising: an impedance circuit having a predetermined impedance penetrating the primary magnetic flux ring and the secondary magnetic flux ring; and the impedance circuit is closed or open circuit. A sensitivity calibration circuit for correcting measurement sensitivity by the measurement unit, provided with an open/close switch for switching to any one of the states, is provided to be switched to correspond to each measurement range, and the sensitivity calibration circuit is closed and closed circuit state. A change in conductivity or a value related to the conductivity by the measuring unit when switching to the open circuit state is calculated as the measurement sensitivity, and the reference sensitivity, which is the measurement sensitivity that is the reference for the measuring unit, is recorded for each measurement range, and It is characterized in that the measurement sensitivity is corrected to a corresponding reference sensitivity.

In such a case, a plurality of circuits for correcting the sensitivity for correcting the measurement sensitivity by the measurement unit are provided so as to be switched in correspondence with each measurement range, and the measurement sensitivity is calculated for each measurement range and corrected to a corresponding reference sensitivity. The measurement precision can be ensured while increasing the measurement precision or widening the measurement range.

According to the present invention configured as described above, since the temperature sensor directly or indirectly measures the temperature of the annular magnetic body, the temperature by the temperature sensor indicates the exact temperature of the annular magnetic body, and by using this temperature, the measurement conductivity is corrected. Conductivity can be determined with high precision.

1 is a schematic diagram showing a conductivity measurement system according to a first embodiment of the present invention.
2 is a perspective view schematically showing a housing member in the same embodiment.
3 is a perspective view schematically showing a housing portion main body in the same embodiment.
4 is a functional block diagram showing the functions of the measurement device in the same embodiment.
5 is a graph showing the relationship between the magnetic body temperature and the measured conductivity in the same embodiment.
6 is a schematic view showing a conventional conductivity measuring system.
7 is a schematic diagram showing a noise loop in the forward loop direction.
8 is a schematic diagram showing a noise loop in the reverse loop direction.
9 is an overall schematic diagram of a conductivity measurement system according to a second embodiment of the present invention.
10 is a circuit diagram showing a part of the annular circuit in the embodiment.
11 is a graph showing an initial state setting method in the same embodiment.
12 is a graph showing an initial state setting method in the same embodiment.
It is a schematic diagram which shows the state which attached the annular circuit in the same embodiment.
14 is an overall schematic view of a conductivity measurement system in other embodiments.
15 is a schematic view showing a conventional conductivity measuring system.
16 is an overall schematic diagram of a conductivity measurement system according to a third embodiment of the present invention.
17 is a hardware configuration diagram of the information processing control device in the same embodiment.
18 is a functional block diagram of an information processing control device in the same embodiment.
19 is a graph showing a sensitivity calibration method in the same embodiment.
20 is an overall schematic diagram of a conductivity measurement system according to a fourth embodiment of the present invention.
21 is an overall schematic diagram of a conductivity measurement system in other embodiments.

<First Embodiment>

The first embodiment of the present invention will be described below with reference to FIGS. 1 to 5.

The conductivity measuring system 100 according to the first embodiment is used, for example, when measuring the conductivity of a liquid sample, such as a material liquid or a cleaning liquid, used in a semiconductor process.

More specifically, as shown in FIGS. 1 and 2, the conductivity measurement system 100 includes an annular tube member 10 into which a liquid sample is introduced, and a primary annular magnetic body through which the annular tube member 10 passes. (21) and the secondary-side annular magnetic body 22, the primary coil 31 and the secondary coil 32 wound around the annular magnetic bodies 21 and 22, and the power supply unit connected to the primary coil 31 ( 5) and a measuring device 6 connected to the secondary coil 32 to measure the conductivity of the measurement object.

1, the primary coil 31 and the secondary coil 32 are not shown.

The annular tube member 10, as shown in Figure 1, to form a flow path of the introduced liquid sample in an annular shape, a first tube member 11 forming a first flow path, and It is comprised of the 2nd pipe member 12 which forms the 2nd flow path branching from 1 flow path and joining to form a loop.

By flowing the flow path described above, the liquid sample forms a closed loop, and in this state, the conductivity of the liquid sample is measured.

In addition, the second pipe member 12 is formed with a protrusion projecting to the second flow path, and a liquid temperature measuring system 8 for measuring the liquid temperature of the liquid sample flowing into the second flow path is provided in the projection. . The liquid temperature measuring system 8 may be provided on the outlet side of the second flow path.

Each of the pipe members 11 and 12 is made of, for example, a synthetic resin such as plastic, the first pipe member 11 penetrates the primary annular magnetic body 21, and the second pipe member 12 is It penetrates the secondary-side annular magnetic body 22.

These annular magnetic bodies 21 and 22 are both Troyder cores made of ferrites having the same shape.

The primary coil 31 and the secondary coil 32 made of, for example, copper wire are wound around each of the annular magnetic bodies 21 and 22.

The primary coil 31 is connected to a power supply unit 5 that applies a predetermined AC voltage to the primary coil 31.

The secondary coil 32 is connected with a measuring device 6 that measures the conductivity of the liquid sample from the induced current generated in the secondary coil 32 when an alternating voltage is applied to the primary coil 31. .

In the present embodiment, the primary-side receiving member 41 and the secondary-side receiving member 42 for receiving each of the annular magnetic bodies 21 and 22 on which the coils 31 and 32 are wound are the tube members 11 and 12 ) Is mounted to surround the outer periphery.

These accommodation members 41 and 42 will be described with reference to Figs. 2 and 3.

The receiving members 41 and 42 are of a double cylinder shape in which an annular accommodation space S for accommodating the annular magnetic bodies 21 and 22 is formed between the outer cylinder portion 432 and the inner cylinder portion 433, and the inner cylinder portion ( 433), the tube members 11 and 12 are fitted.

In addition, the receiving members 41 and 42 are separated from the outer cylinder portion 432 and the inner cylinder portion 433 by an annular bottom plate 431 interposed between the outer cylinder portion 432 and the inner cylinder portion 433. A protrusion for mounting the temperature sensor 45 on the reverse side is formed.

More specifically, as shown in FIG. 2, the receiving members 41 and 42 are composed of a receiving body main body 43 forming the receiving space S and a cover 44 sealing the receiving space S. It is.

The housing main body 43 is formed from an annular bottom plate 431, an outer cylinder portion 432 formed from an outer peripheral portion of one surface of the annular bottom plate 431, and an inner peripheral portion. It has an inner cylinder portion 433 formed.

And the annular space surrounded by these annular bottom plate 431, the outer cylinder part 432, and the inner cylinder part 433 is formed as said accommodation space S.

In order to accommodate the annular magnetic bodies 21 and 22 in which the coils 31 and 32 are wound in the accommodation space S such that the gap between them is the smallest, the inner diameter of the outer cylinder 432 is an annular magnetic body 21, It is slightly larger than the outer diameter of 22), and the outer diameter of the inner cylinder portion 433 is formed slightly smaller than the inner diameter of the annular magnetic bodies 21 and 22.

Further, the inner cylinder portion 433 is formed such that the inner diameters of the inner cylinder portion 433 and the outer diameters of the pipe members 11 and 12 are the same so that the pipe members 11 and 12 are fitted without rattling.

The cover 44 is attached to the above-described receiving portion main body 43 and detachably, for example, and is attached to the receiving portion main body 43 to seal the receiving space S.

More specifically, the cover 44 is a flat plate forming an annular shape, and has an outer diameter equal to the outer diameter of the outer cylinder portion 432 and an inner shape equal to the inner diameter of the inner cylinder portion 433.

And in this embodiment, the temperature sensor mounting part 434 which forms a solid cylindrical shape for mounting the temperature sensor 45, the outer cylinder part 432 and the inner cylinder part (from the other side of the annular bottom plate 431) 433) and the receiving portion main body 43 is formed integrally with the reverse side.

The temperature sensor mounting portion 434 is provided with a temperature sensor mounting hole 435 for inserting the temperature sensor 45 from the outer peripheral surface of the temperature sensor mounting portion 434 into the inside.

As shown in Fig. 3, in the housing portion 43 of either of the receiving members 41, 42, in this temperature sensor mounting hole 435, for example, a temperature sensor such as platinum resistance for temperature detection 45 is mounted.

The primary-side receiving member 41 and the secondary-side receiving member 42 configured as described above are made of metals, such as iron, having the same shape as each other, and different from the annular bottom plate 431 in this embodiment. It is excreted so that the side faces.

Next, the measurement device 6 for measuring the conductivity of the liquid sample from the induced current generated in the secondary coil 32 will be described.

The measurement device 6 is provided with a CPU, a memory, an A/D converter, and the like, not shown, by storing a predetermined program in the memory and cooperatively operating the CPU or peripheral devices according to the program. As shown in Fig. 4, the functions as the measurement section 61, the temperature characteristic data storage section 62, and the correction section 63 are exerted.

The measurement unit 61 measures the measurement conductivity based on the induced current generated in the secondary coil 32 when a predetermined alternating voltage is applied to the primary coil 31, and a measurement signal indicating the value is described later. This is output to the correction unit 63.

The temperature characteristic data storage unit 62 stores temperature characteristic data, which is data representing the relationship between the magnetic body temperature and the measured conductivity.

Specifically, the temperature characteristic data storage unit 62 is obtained by measurement of a simulated resistance (not shown), as shown at the top of FIG. 5, from the relationship between the magnetic body temperature and the measurement conductivity, as shown at the bottom of FIG. 5. Similarly, the standardized value, which is the value of the measured conductivity at each magnetic body temperature, is stored as the temperature characteristic data when the reference temperature, which is the predetermined magnetic body temperature, for example, the reference conductivity representing the measured conductivity at 25° C. is 1.0. It is.

The correction unit 63 receives the measurement signal from the measurement unit 61, the storage member temperature signal indicating the temperature of the storage member from the temperature sensor 45, and the temperature characteristic data from the temperature characteristic data storage unit 62. Thus, the measured conductivity is corrected, and the corrected conductivity is displayed on the display 7 or the like.

More specifically, first, the housing member temperature is regarded as the magnetic body temperature, and a standardized value for the magnetic body temperature is obtained from the temperature characteristic data.

Then, the corrected conductivity is calculated by dividing the measured conductivity by the standardized value.

In addition, the correction unit 63 is configured to calculate the conductivity by assuming that the relationship between the magnetic body temperature and the normalized value does not depend on the resistance value of the simulated resistance (not shown) and is a constant relationship.

In addition, the correction unit 63 may receive the liquid temperature data obtained by the liquid temperature measurement system 8 and correct the measurement conductivity as a liquid temperature parameter.

Specifically, based on the liquid temperature data obtained by the liquid temperature measuring system 8, a method of correcting the liquid sample to obtain the conductivity at 25°C can be given.

According to the first embodiment configured as described above, the annular magnetic bodies 21 and 22 are accommodated in the metal accommodating members 41 and 42, and between the annular magnetic bodies 21 and 22 and the accommodating members 41 and 42. Since the heat transfer property is good, it is possible to accurately obtain the conductivity by considering the temperature of the receiving member as the temperature of the magnetic body and correcting the measurement conductivity.

In addition, the conductivity at various temperatures can be converted to the conductivity at a predetermined temperature, and comparison is facilitated.

Further, since the annular magnetic bodies 21 and 22 in which the coils 31 and 32 are wound are accommodated in the accommodation space S so as to have the smallest gap, between the annular magnetic bodies 21 and 22 and the accommodating members 41 and 42. The heat transfer property is good, and high-precision measurement is possible.

Moreover, since the accommodation space S which accommodates the annular magnetic bodies 21 and 22 is closed, the temperature of the accommodating member and the temperature of the magnetic body become the same temperature.

Since each of the accommodating members 41 and 42 has the same shape made of a metal such as iron and is arranged so that each annular bottom plate 431 is in contact, the accommodating member temperature of each accommodating member 41 and 42 is the same. As a result, the temperature sensor 45 may be attached to any of the accommodating members 41 and 42.

In addition, since the temperature sensor 45 is inserted into the inside from the outer circumferential surface of the temperature sensor mounting portion 434, it is possible to detect the receiving member temperature in the vicinity of the annular magnetic bodies 21 and 22 rather than being mounted on the outer circumferential surface or the inner circumferential surface. The temperature of the receiving member to be detected becomes a more accurate magnetic material temperature.

When the measurement object is described, the receiving members 41 and 42 are made of metal, but since the annular tube member 10 into which the liquid sample is introduced is made of synthetic resin, the conductivity can be measured even with a corrosive liquid sample.

In addition, this invention is not limited to 1st Embodiment.

For example, in the first embodiment, the temperature sensor 45 is attached to either the primary-side receiving member 41 or the secondary-side receiving member 42, but the temperature sensors are attached to the respective receiving members 41 and 42. (45) may be attached.

By configuring in this way, even when the size and shape of the primary side receiving member 41 and the secondary side receiving member 42 are different, or even when the dimensions of the first pipe member 11 and the second pipe member 12 are different, , By detecting the temperature of each of the accommodating members 41 and 42 and correcting the measurement conductivity using these temperatures as parameters, it becomes possible to obtain the conductivity accurately.

In addition, in the first embodiment, the temperature sensor 45 was attached to the temperature sensor mounting hole 435, but in order to facilitate the manufacture of the housing part body 43, the outer peripheral surface of the housing part body 43 or The temperature sensor 45 may be attached to the inner peripheral surface.

In addition, although the temperature sensor mounting part 434 formed a semi-cylindrical shape of a solid, its shape, such as a cylindrical shape or a partial cylindrical shape, is not limited.

When the measuring device 6 is described, the temperature characteristic data storage unit 62 may store standardized values at several representative temperatures.

In this case, the standardized value corresponding to the magnetic body temperature other than the representative temperature may be configured so that the standardized value at the representative temperature can be obtained by interpolating.

The correction unit 63 is configured to calculate the correction conductivity by assuming that the relationship between the magnetic body temperature and the standardized value does not depend on the resistance value of the simulated resistance, but in order to perform more accurate correction, a plurality of resistance values are provided. The correction measurement conductivity may be calculated based on the relationship between the magnetic body temperature obtained from the simulated resistance and the standardized value.

Moreover, you may mount all the accommodation members 41 and 42 in parallel to the 1st pipe member 11 or the 2nd pipe member 12 in series.

Moreover, in 1st Embodiment, although it was used when measuring the conductivity of a liquid sample, the concentration of the measurement object contained in a liquid sample can also be measured from the measured conductivity.

Moreover, it can also be used as an ohmmeter for measuring the resistance value of a liquid sample.

<second embodiment>

The second embodiment of the present invention will be described below with reference to the drawings.

The conductivity measuring system 100x according to the second embodiment, as shown in Fig. 9, is used in, for example, a semiconductor process, when measuring the conductivity of a liquid sample, such as a material liquid or a cleaning liquid, to be measured. As used, the annular pipe member 3x to which the measurement object is introduced, the primary coil 1x and the secondary coil 2x mounted on the annular pipe member 3x, and the primary coil 1x are connected Power supply 5x, measurement section 6x connected to secondary coil 2x, primary side magnetic flux ring 11x formed by primary coil 1x and secondary coil 2x formed by It consists of an annular circuit 4x mounted to penetrate the secondary magnetic flux ring 12x.

The annular tube member 3x is made of, for example, a synthetic resin such as plastic, and the second tube member (31x) and the second tube member (32) joining to form a loop by branching from the first tube member (31x) 32x).

The first tube member (31x), so that the first tube member (31x) is equipped with a troydal core, the inside of this troydal core, so that the primary magnetic flux ring (11x) is formed, the troydal The primary coil 1x is wound around the core. Likewise, the second tube member 32x is provided with a troydal core mounted on the second tube member 32x, so that a secondary magnetic flux ring 12x is formed inside the troyder core. The secondary coil (2x) is wound around the trojan core.

Such a troyder core is made of, for example, a cylindrical ferrite, and both the primary coil 1x and the secondary coil 2x are made of coils such as copper wire, for example.

The primary coil 1x is connected to a power supply unit 5x that applies a predetermined alternating voltage, and when the secondary coil 2x is applied with an alternating voltage to the primary coil 1x, the secondary coil 2x The measurement section 6x for measuring the conductivity of the measurement target is connected from the output induction current which is the induced current generated in ).

Next, the annular circuit 4x will be described with reference to FIGS. 9 and 10.

The annular circuit 4x includes a primary wiring 41x passing through the primary magnetic flux ring 11x, a secondary wiring 42x passing through the secondary magnetic flux ring 12x, and a primary wiring 41x. It consists of the impedance variable element 43x provided in the, and the inversion mechanism 44x connected to the primary-side wiring 41x and the secondary-side wiring 42x.

The impedance variable element 43x and the inverting mechanism 44x are formed on a substrate 45x. The substrate 45x includes a first input terminal 411x connected to one end of the primary side wiring 41x, and A second input terminal 412x connected to the other end, a first output terminal 421x connected to one end of the secondary-side wiring 42x, and a second output terminal 422x connected to the other end are provided.

The impedance variable element 43x is provided on the primary side wiring 41x connected to the first input terminal 411x on the substrate 45x in the present embodiment, for example, depending on the position of the movable contact. It consists of a variable resistor element that changes the value.

The inverting mechanism 44x is connected to a positive loop connection state in which the first input terminal 411x and the first output terminal 421x are connected, and the second input terminal 412x and the second output terminal 422x are connected. , A switch 441x switchable by interlocking a reverse loop connection state connecting the first input terminal 411x and the second output terminal 422x, and connecting the second input terminal 412x and the first output terminal 421x ), so that the loop direction of the annular circuit 4x can be selectively switched.

Next, an initial state setting method of the conductivity measuring system 100x according to the present embodiment will be described with reference to FIGS. 9 to 13.

Initially, the impedance of the annular circuit 4x is set to a sufficiently large impedance by the impedance variable element 43x, so that even if a predetermined alternating voltage is applied to the primary coil 1x, current does not flow through the annular circuit 4x. In a non-existing state, that is, a state where the conductivity of the annular circuit 4x is zero.

In addition, the loop direction of the annular circuit 4x is switched in the forward loop direction (state in Fig. 10) by the switch 441x of the inversion mechanism 44x.

In the above-described state, when a predetermined alternating voltage is applied to the primary coil 1x by the power supply unit 5x, the output induced current obtained by the measurement unit 6x is the first noise, as shown in FIG. the first is the noise current I ₀ and the second noise I 'to I ₀ + I plus one another, caused by.

Here, when the impedance of the annular circuit 4x is gradually lowered to increase the electrical conductivity, an additional induced current, which is an induced current generated in the secondary coil 2x by the current induced in the annular circuit 4x, is generated.

When this additional induced current is generated, as the conductivity of the annular circuit 4x increases, the output induced current changes, but this change varies depending on the loop direction of the noise loop.

When the loop direction of the noise loop is the positive loop direction, since the additional induced currents are added to the output induced currents, the output induced current starts to increase with the increase in the conductivity of the annular circuit 4x.

When the loop direction of the noise loop is the reverse loop direction, since the additional induced current is subtracted from the output induced current, as the conductivity of the annular circuit 4x increases, the output induced current starts to decrease.

Among the above, when the output induction current increases with the increase in the conductivity of the annular circuit 4x, the inversion mechanism 44x so that the output induction current decreases with the increase in conductivity of the annular circuit 4x. By reversing the loop direction of the annular circuit 4x, it is set to the reverse loop direction.

Moreover, among the above, when the output induced current decreases with an increase in the conductivity of the annular circuit 4x, the loop direction of the annular circuit 4x is set to the forward loop direction.

By setting the loop direction of the annular circuit 4x in this way, the output induced current has a minimum point that changes from decreasing to increasing as the conductivity of the annular circuit 4x increases.

This minimum is a state where the influence of the first noise on the output induced current is minimized.

The impedance of the annular circuit 4x in this state is set to R ₀ .

In the state where the impedance of the annular circuit 4x is set to R ₀ , as shown in FIG. 12, in the region where the effective conductivity of the measurement object is less than or equal to a certain level, the output induced current and the measurement object A nonlinear region in which the relationship of effective conductivity becomes nonlinear is formed.

Accordingly, the impedance of the annular circuit 4x is gradually lowered from R ₀ by the impedance variable element 43x, and the maximum impedance R ₁ is set among the impedances in which the relationship between the output induced current and the effective conductivity of the measurement object becomes linear. .

As described above, the state in which the loop direction and the impedance of the annular circuit 4x are set is the initial state before measuring the conductivity of the measurement object.

According to the initial state setting method of the conductivity measuring system 100x according to the second embodiment configured as described above, the annular circuit 4x is provided with the impedance variable element 43x and the inverting mechanism 44x for reverse-reversing the loop direction. Since it is provided to penetrate the primary-side magnetic flux ring 11x and the secondary-side magnetic flux ring 12x, as a result of minimizing the effect of the first noise on the output induced current, the output induced current and measurement under the influence of the second noise The state in which the loop direction and the impedance of the annular circuit 4x are set so as to avoid the nonlinear region where the relationship between the effective conductivity of the object becomes nonlinear can be set as an initial state before measurement, and even if the object is measured with a lower conductivity. It becomes possible to measure with high precision.

Also, since the impedance of the annular circuit 4x is set such that the relationship between the output induced current and the effective conductivity of the object to be measured is approximately the largest of the impedances that are approximately linear, the influence of the second noise and the output induced current As a result of avoiding the nonlinear region where the relationship between the effective conductivity of the measurement object becomes nonlinear, the output induced current when the effective conductivity of the measurement object is zero is minimized, so that the measurement range up to the measurement upper limit of the output induced current can be widened. Can, the measurement range is widened.

When the setting of the initial state is described, by switching the switch 441x, the direction through which the current induced in the annular circuit 4x passes through the secondary magnetic flux ring 12x is selectively switched, and the secondary magnetic flux ring 12x ), the loop direction of the annular circuit 4x can be set in a direction that cancels out the current flowing through the noise loop surely.

In addition, since the predetermined alternating voltage is applied to the primary coil 1x after setting the impedance of the annular circuit 4x to a sufficiently large impedance, after setting the loop direction as described above, only the impedance is lowered. It can be set to the impedance R ₀ which is definitely the smallest point.

In addition, since the impedance variable element 43x is provided between the first input terminal 411x and the inverting mechanism 44x, it does not depend on the loop direction of the annular circuit 4x, but with one impedance variable element 43x. The impedance of the annular circuit 4x can be set.

When the formation of the annular circuit 4x is explained, simply connecting the substrate 45x to the wiring passing through the primary-side magnetic flux ring 11x and the secondary-side magnetic flux ring 12x makes it easy to connect the annular circuit 4x. Can form.

In addition, if the loop direction and the impedance of the annular circuit 4x are set once as described above, then, in order to set the conductivity measuring system 100x having the same configuration as the wiring or the circuit on the substrate to the same initial state, the It is only necessary to mount the annular circuit 4x having the loop direction and the impedance so as to penetrate through the primary magnetic flux ring 11x and the secondary magnetic flux ring 12x.

In this case, as shown in Fig. 13, the annular circuit 4x may be provided with the fixed resistor 431x for the annular circuit 4x to have the above impedance.

The loop direction of the annular circuit 4x is equipped with an annular circuit 4x when the output induced current when the conductivity of the object to be measured increases from zero when the annular circuit 4x is separated increases monotonically. By doing so, the output induced current is set to decrease compared to the state in which the annular circuit 4x is separated.

In addition, when the output induced current when the conductivity of the measurement object is increased from zero in the state where the annular circuit 4x is separated has a minimum point, it is set so that the minimum point disappears by mounting the annular circuit 4x. have.

13 shows a case where the noise loop is in the reverse loop direction and the loop direction of the annular circuit 4x is set to the forward loop direction.

The resistance value of the fixed resistor 431x is an output induced current at a minimum point where the output induced current when the conductivity of the object to be measured increases from zero to increase and output with the annular circuit 4x attached. As a resistance value having a value smaller than the resistance value where the induced current coincides, the relationship between the output induced current and the effective conductivity of the object to be measured is set to be approximately the maximum resistance value among the resistance values that are approximately linear.

Note that the present invention is not limited to the second embodiment.

For example, with respect to the setting method of the initial state, in the second embodiment, a predetermined alternating voltage was applied to the primary coil 1x after setting the impedance of the annular circuit 4x to a sufficiently large impedance, After setting to an arbitrary impedance, a predetermined alternating voltage may be applied to the primary coil 1x.

In this case, the impedance R ₀ which becomes the minimum point is set by increasing or decreasing the impedance of the annular circuit 4x.

Moreover, after setting the loop direction of the annular circuit 4x to the direction of canceling the current flowing through the noise loop, the impedance of the annular circuit 4x is gradually increased from a sufficiently small impedance to gradually increase the impedance and the output induced current. May be set to an impedance R ₁ in which the relationship of varies from linear to nonlinear.

In the above-described setting method, the procedure for setting the impedance of the annular circuit 4x to the impedance R ₀ can be omitted.

When the influence of the output induced current path due to the second noise is small and does not adversely affect the measurement of conductivity, the impedance of the annular circuit 4x is set to the impedance R ₀ at the smallest point, that is, the first noise It is good to set the state which minimized the influence by the initial state.

The loop direction of the annular circuit 4x and the impedance may be set automatically by a computer.

In this case, the computer changes the impedance of the annular circuit 4x by the impedance variable element 43x, so that the smallest point at which the output induced current of the secondary coil 2x changes from decrease to increase according to the change in impedance As shown, the relationship between the loop direction setting unit for setting the loop direction of the annular circuit 4x by the inverting mechanism 44x and the impedance of a value smaller than the impedance at the smallest point is approximately linear. Of the impedances to be obtained, an impedance setting unit that sets the impedance of the annular circuit 4x by the impedance variable element 43x so as to be approximately maximum impedance may be provided.

If it is such a thing, the initial state setting of the said 2nd embodiment mentioned above is performed automatically, and a user's working process before measurement can be reduced.

The measurement target was a liquid sample in the second embodiment, but may be a metal or the like forming a closed loop.

In the second embodiment, the impedance variable element 43x and the inversion mechanism 44x are formed on the substrate 45x, but are not necessarily formed on the substrate 45x.

In addition, as shown in FIG. 14, both the primary coil 1x and the secondary coil 2x may be mounted to the second tube member 32x in parallel in series.

Moreover, in the said 2nd Embodiment, although it was used when measuring the conductivity of a liquid sample, the concentration of the measurement object contained in a liquid sample can also be measured from the measured conductivity.

Moreover, it can also be used as an ohmmeter for measuring the resistance value of a liquid sample.

<third embodiment>

The third embodiment of the present invention will be described below with reference to Figs.

The conductivity measurement system 100z according to the third embodiment, as shown in FIG. 16, is used in, for example, used in a semiconductor process to measure the conductivity of a measurement target such as a material liquid or a cleaning liquid. , A predetermined alternating voltage is applied to the annular tube member 10z to which the measurement object is introduced, the primary coil 11z and the secondary coil 12z, and the primary coil 11z attached to the annular tube member 10z. An information processing control device 14z for measuring the conductivity of the measurement target from an applied power supply unit 13z, an induced current generated in the secondary coil 12z, and a sensitivity calibration circuit 2z for correcting measurement sensitivity It is composed of.

The annular tube member 10z is made of, for example, a synthetic resin such as plastic, and a second tube member (2) joining the first tube member 101z and the first tube member 101z to form a loop 102z).

The first tube member 101z is penetrated so that a Trojan core is mounted on the first tube member 101z, and the Troider is formed so that a primary magnetic flux ring 111z is formed inside the Trojan core. The primary coil 11z is wound around the core. Likewise, the second tube member 102z is provided with a Trojan core attached to the second tube member 102z, and a secondary magnetic flux ring 112z is formed inside the Trojan core. The secondary coil 12z is wound around the trojan core.

Such a trojan core is made of, for example, a cylindrical ferrite, and both the primary coil 11z and the secondary coil 12z are made of, for example, coils such as copper wire.

A power supply unit 13z is connected to the primary coil 11z, and when a predetermined AC voltage is applied from the power supply unit 13z to the primary coil 11z, through a measurement target introduced into the annular tube member 10z , An induced current depending on the conductivity of the measurement object is generated in the secondary coil 12z.

The induced current generated in the secondary coil 12z is converted into direct current by the rectifier 15z, amplified at a predetermined amplification rate by the amplifier 16z, and input to the information processing control device 14z.

As shown in Fig. 17, the information processing control device 14z includes, in addition to the CPU 51z, an input means 54z such as a memory 52z, an input/output channel 53z, a keyboard, and an output means 55z such as a display. ), and analog-to-digital conversion circuits such as an A/D converter 56z and a D/A converter 57z are connected to the input/output channel 53z.

Then, the CPU 51z and its peripheral devices cooperate in accordance with a program stored in a predetermined area of the memory 52z, so that the information processing control device 14z, as shown in FIG. 18, is a measuring unit 141z. ), the range switching unit 142z, the sensitivity calibration circuit switching unit 143z, the measurement sensitivity calculating unit 31z, the reference sensitivity storage unit 32z, and the calibration unit 33z.

The measurement unit 141z is based on, for example, reference data indicating a relationship between the induced current and the conductivity as a proportional relationship stored in the reference data storage unit 144z set in a predetermined area of the memory 52z. , Conductivity is measured from the induced current generated in the secondary coil 12z.

The range switching unit 142z outputs a range signal for determining the measurement range of the measurement unit 141z to the amplifier 16z and the measurement unit 141z, and changes the amplification factor of the amplifier 16z, thereby measuring unit It is to switch the measurement range of (141z) to any of a plurality.

The sensitivity correction circuit switching section 143z is used, for example, to store the correspondence between the measurement range and the sensitivity correction circuit 2z used for calibration, which is set in a predetermined area of the memory 52z. Sensitivity corresponding to each measurement range among the plurality of sensitivity calibration circuits 2z used for calibration based on the used circuit data from the circuit storage section 145z and the range signal obtained from the range switching section 142z described above. It is to switch to the calibration circuit 2z.

In detail, the circuit for correcting sensitivity 143z outputs an open/close signal to the on/off switch 22z described later based on the used circuit data and the acquired range signal, thereby closing each sensitivity correcting circuit 2z. Alternatively, by switching to any one of the open circuit states, the sensitivity calibration circuit 2z is switched in response to each measurement range.

Next, with reference to Figs. 16 and 18, a description will be given of a sensitivity correction circuit 2z provided in order to correct the measurement sensitivity of the measurement unit 141z for each measurement range.

Each sensitivity calibration circuit 2z is disposed in parallel with the measurement object introduced into the annular tube member 10z, and is an electrical cable (closed by connecting a resistor 212z and both terminals of the resistor 212z). 211z) and an open/close switch 22z provided on the electric cable 211z to switch the impedance circuit 21z to either a closed circuit state or an open circuit state.

In this embodiment, as shown, the electric cable 211z is common to each impedance circuit 21z, and is provided to pass through the primary magnetic flux ring 111z and the secondary magnetic flux ring 112z.

A plurality of resistors 212z for determining the resistance value (i.e., the conductivity of the sensitivity correction circuit 2z) of the sensitivity correction circuit 2z corresponding to each measurement range is connected to the electric cable 211z in parallel. .

In this embodiment, the resistance value of each resistor 212z is a value such that the conductivity of the sensitivity correcting circuit 2z corresponding to each measurement range becomes an upper limit of measurement of the measurement range.

The on-off switch 22z is a two-terminal analog switch configured to operate independently based on the open/close signal from the circuit switching unit 143z for sensitivity calibration, as shown.

The opening/closing switch 22z configured as described above switches each of the impedance circuits 21z to any of the closed-circuit state or the open-circuit state as described above, and at the same time measures the measurement ranges from a plurality of provided sensitivity correction circuits 2z. Correspondingly, it is possible to switch to the sensitivity correction circuit 2z used for calibration.

In addition, since these opening/closing switches 22z operate independently, it is also possible to set the plurality of impedance circuits 21z at the same time to the closed circuit state, so that the plurality of sensitivity correction circuits 2z in the closed circuit state are each impedance. Can be regarded as one sensitivity calibration circuit 2z having a synthesized impedance.

In the state in which a predetermined alternating voltage is applied to the primary coil 11z by the opening/closing switch 22z, the sensitivity correction circuit 2z corresponding to each measurement range is switched from the open circuit state to the closed circuit state. In the lower surface, an induced current depending on the impedance of the sensitivity correction circuit 2z (that is, the conductivity of the sensitivity correction circuit 2z) is generated in the secondary coil 12z, and is obtained by the measurement unit 141z. The conductivity or the value related to the conductivity for calculating the conductivity changes.

Subsequently, referring to FIGS. 16, 18, and 19, the measurement sensitivity of the measurement unit 141z is calculated and corrected based on the change in the conductivity or the conductivity-related value obtained by the measurement unit 141z described above. The measurement sensitivity calculation section 31z, reference sensitivity storage section 32z, and calibration section 33z are described.

The measurement sensitivity calculation unit 31z calculates the measurement sensitivity of the measurement unit 141z based on the electric conductivity obtained by the measurement unit 141z or a change in the conductivity-related value. In this embodiment, the circuit for sensitivity calibration When (2z) is changed from the open circuit state to the closed circuit state, the change in the current value obtained by the measurement unit 141z is calculated as the measurement sensitivity.

The reference sensitivity storage unit 32z is set in a predetermined area of the memory 52z, and stores reference sensitivity, which is a measurement sensitivity that becomes a reference for each measurement range.

More specifically, the reference sensitivity storage unit 32z sets the sensitivity correction circuit 2z corresponding to each measurement range from an open circuit state to a closed circuit state, for example, at an initial time, such as when shipped from the factory. The change in the current value obtained by the measurement unit 141z when switching is stored as a reference sensitivity.

The calibration unit 33z acquires the measurement sensitivity calculated by the measurement sensitivity calculation unit 31z in each measurement range and the corresponding reference sensitivity stored in the reference sensitivity storage unit 32z, and measures measurement sensitivity as a reference. Sensitivity is calibrated to be the sensitivity.

In the present embodiment, the calibration unit 33z outputs a calibration signal for setting the measurement sensitivity to the reference sensitivity to the measurement unit 141z, and the sensitivity calibration circuit 2z is closed from the open circuit state. At this time, the change in the current value obtained by the measurement unit 141z is corrected to be the change in the current value stored in the reference sensitivity storage unit 32z as the reference sensitivity.

In addition, a warning signal is output to the information processing control device 14z when the conductivity obtained by the measurement unit 141z when the sensitivity calibration circuit 2z is closed is exceeded. A function as a warning unit 34z (not shown) is additionally provided.

According to the conductivity measurement system 100z according to the third embodiment configured as described above, a plurality of sensitivity correction circuits 2z for correcting the measurement sensitivity by the measurement unit 141z are provided to be switched in correspondence with each measurement range. Therefore, the measurement sensitivity can be accurately corrected for each measurement range, and measurement precision can be secured while increasing the measurement precision or widening the measurement range.

In addition, since the measurement sensitivity calculating unit 31z calculates the measurement sensitivity of each measurement range, and the calibration unit 33z corrects the measurement sensitivity to be the corresponding reference sensitivity stored in the reference sensitivity storage unit 32z. In addition, it is possible to improve the workability by automating the sensitivity calibration.

In addition, since the resistance value of each resistor 212z is a value at which the conductivity of the sensitivity calibration circuit 2z corresponding to each measurement range becomes an upper limit of measurement of the measurement range, accurate calibration in each measurement range is performed. can do.

By simultaneously putting the plurality of impedance circuits 21z into the closed-loop state, the plurality of sensitivity correction circuits 2z that are closed are regarded as one sensitivity correction circuit 2z having a composite impedance obtained by synthesizing each impedance. It is possible to calibrate the sensitivity in each measurement range with the impedance circuit 21z smaller than the number of measurement ranges.

Further, by using a plurality of sensitivity calibration circuits 2z to obtain a plurality of measurement values by the measurement unit 141z, it is also possible to confirm the linearity or zero point of the change in measurement sensitivity.

In addition, since the information processing control device 14z has a function as the warning unit 34z, the user can measure the conductivity by the measurement unit 141z when the sensitivity calibration circuit 2z is closed. It is easy to recognize that sensitivity calibration cannot be performed when the measurement upper limit is exceeded.

In this case, by making the impedance circuit 21z having an impedance greater than the impedance circuit 21z of the sensitivity correction circuit 2z corresponding to this measurement range closed, the conductivity by the measurement unit 141z is the measurement range. It enters inside, and sensitivity calibration is possible without changing the measurement range.

Next, the fourth embodiment will be described. In addition, it is assumed that the same reference numerals are given to elements showing the same configuration as in the third embodiment.

In the above-described third embodiment, the on/off switch 22z is a two-terminal analog switch provided in each sensitivity calibration circuit 2z, and operates independently of each other, thereby closing each sensitivity calibration circuit 2z. Alternatively, it is to switch to any of the open circuit states, but in the fourth embodiment, as shown in FIG. 20, the on/off switch 22z is one of a terminal provided on one side and a plurality of terminals provided on the other side. It is configured to close the terminals between and, so that any one of the plurality of sensitivity calibration circuits 2z can be switched to the closed circuit state.

Even if the conductivity measuring system 100z of the fourth embodiment configured as described above can switch the sensitivity correction circuit 2z for each measurement range, the measurement sensitivity can be accurately calibrated for each measurement range, and the switch is opened and closed. The switching of the open-circuit state or closed-loop state of the sensitivity calibration circuit 2z by (22z) and the switching to the sensitivity calibration circuit 2z corresponding to each measurement range are facilitated.

In addition, this invention is not limited to the said 3rd and 4th embodiment.

For example, when the sensitivity is calibrated while the liquid sample is filled in the annular tube member 10z during measurement, as in the present embodiment, the resistance value of each resistor 212z is for sensitivity calibration corresponding to each measurement range. If the conductivity of the circuit 2 is the upper limit of measurement of the measurement range, the conductivity obtained by the measurement unit 141z exceeds the upper limit of measurement of the measurement range, and sensitivity calibration cannot be performed. Accordingly, by setting the resistance value of each resistor 212z to a value smaller than the upper limit of the measurement, sensitivity may be corrected even during the measurement of the conductivity of the measurement target.

Moreover, the resistance value of each resistor 212z does not need to be different, respectively, and some resistance values of the resistors 212z may be the same.

In addition, it is not necessary that the sensitivity correction circuit 2z used at the time of calibration for each measurement range is different, and some of the sensitivity correction circuits 2z corresponding to each measurement range may be the same.

Further, when the warning section 34z outputs a warning signal, the sensitivity correction circuit switching section 143z has a greater impedance than the sensitivity correction circuit 2z corresponding to each measurement range, and the sensitivity correction circuit 2z You may want to automatically switch to.

By configuring as described above, it is possible to reliably correct the sensitivity of the measurement unit 141z even during measurement of the conductivity of the measurement target.

In the third embodiment, the measurement sensitivity calculating unit 31z is configured to calculate the measurement sensitivity based on the change in the current value obtained by the measurement unit 141z, but the conductivity obtained by the measurement unit 141z It may be configured to calculate the measurement sensitivity based on the variation of.

The calibration unit 33z outputs the calibration signal to the measurement unit 141z, and the sensitivity is calibrated so that the measurement sensitivity becomes the reference sensitivity. You may calibrate.

Further, the range switching unit 142z was configured to output a range signal to the amplifier 16z to change the amplification factor, but by outputting a range signal to the power supply unit 13z and changing the magnitude of the applied voltage, the measurement unit 141z It may be configured to switch the measurement range of.

In addition, as shown in FIG. 21, both the primary coil 11z and the secondary coil 12z may be attached to the second pipe member 102z in series.

Moreover, in the said 3rd embodiment, although it was used when measuring the conductivity of a liquid sample, the concentration of the measurement object contained in a liquid sample can also be measured from the measured conductivity.

Moreover, it can also be used as an ohmmeter for measuring the resistance value of a liquid sample.

Moreover, although the measurement object was liquid, the metal forming a closed loop may be sufficient.

In addition, the present invention is not limited to the above-described embodiments, and various modifications are possible without departing from the spirit.

100: conductivity meter
10: absence of annular tube
21: primary side magnetic material
22: Secondary annular magnetic body
31: primary coil
32: secondary coil
41: Primary side receiving member
42: secondary side receiving member
43: housing body
435: temperature sensor mounting hole
45: temperature sensor
S: accommodation space
100x: conductivity meter
1x: primary coil
2x: secondary coil
4x: annular circuit
41x: primary wiring
42x: secondary wiring
43x: Impedance variable element
44x: reversing mechanism
441x: Switch
100z: conductivity meter
14z: Information processing control device
141z: Measurement unit
142z: Range switching unit
143z: Circuit switching section for sensitivity calibration
2z: Sensitivity calibration circuit
21z: Impedance circuit
22z: open/close switch
31z: Measurement sensitivity calculator
32z: reference sensitivity memory
33z: correction unit

Claims (25)

The primary coil forming the primary magnetic flux ring and the secondary coil forming the secondary magnetic flux ring, and a power supply unit for applying a predetermined alternating voltage to the primary coil, and the primary coil and secondary coil for their magnetic flux ring In the state in which the measurement object forming the closed loop passes through, in the initial state setting method of the conductivity measuring system having a measuring unit for measuring the conductivity of the measurement object from the output induction current which is the induced current generated in the secondary coil In,
An annular circuit penetrating the primary magnetic flux ring and the secondary magnetic flux ring, an impedance variable element that changes the impedance of the annular circuit and a loop direction that is a through direction of the annular circuit with respect to the magnetic flux ring, is reversed. A step of providing an annular circuit with an inverting mechanism to instruct,
Has a step of setting the loop direction of the annular circuit by the inversion mechanism,
When the loop direction changes the impedance of the annular circuit by the impedance variable element by applying a predetermined alternating voltage to the primary coil, the output induced current changes from decreasing to increasing according to the change in impedance. A method for setting an initial state of a conductivity measuring system, characterized in that it is a direction in which a point appears. The method according to claim 1,
A method for setting an initial state of a conductivity measuring system, characterized in that the impedance variable element is adjusted to have a maximum impedance among impedances in which the relationship with the output induced current is linear as an impedance having a value smaller than the impedance at the smallest point. . The method according to claim 1,
The annular circuit further comprises a primary-side wiring passing through the primary-side magnetic flux ring and a secondary-side wiring passing through the secondary-side magnetic flux ring,
The reverse mechanism connects one end and the other end of the primary-side wiring to one end and the other end of the secondary-side wiring, respectively, and one end and the other end of the primary-side wiring, respectively, and the other end of the secondary-side wiring. And a switch for switching a reverse loop connection state that is connected to one end,
A method for setting an initial state of a conductivity measuring system, characterized in that the impedance variable element is provided on the primary side wiring or on the secondary side wiring. The method according to claim 1,
A method for setting an initial state of a conductivity measuring system, characterized in that the impedance variable element is a variable resistance element that changes a resistance value according to the position of a movable contact. The primary coil forming the primary magnetic flux ring and the secondary coil forming the secondary magnetic flux ring, and a power supply unit for applying a predetermined alternating voltage to the primary coil, and the primary coil and secondary coil for their magnetic flux ring In the state in which the measurement object forming the closed loop passes through, in the conductivity measuring system having a measuring unit for measuring the conductivity of the measurement object from the output induction current that is the induced current generated in the secondary coil,
And an annular circuit having a constant impedance mounted to penetrate the primary magnetic flux ring and the secondary magnetic flux ring, wherein the annular circuit is configured to generate an additional induced current that is an induced current generated in the secondary coil. Conductivity measuring system. The method according to claim 5,
When the output induction current monotonically increases when the conductivity of the measurement object is increased from zero while the annular circuit is separated, the output induction current is the annular circuit by mounting the annular circuit. And a loop direction that is a through direction of the annular circuit with respect to the magnetic flux ring is set so as to decrease compared to the separated state. The method according to claim 5,
When the output induced current when the conductivity of the measurement object is increased from zero in the state where the annular circuit is disconnected appears in the case where a small point appears to change from decrease to increase, by mounting the annular circuit, the small point disappears. A conductivity measuring system characterized in that a loop direction, which is a through-direction to the magnetic flux ring, of the annular circuit is set. The method according to claim 6,
When the impedance of the annular circuit increases the conductivity of the object to be measured from zero, the output induced current at a minimum point where the output induced current changes from decrease to increase and the output induction with the annular circuit mounted A conductivity measuring system characterized in that the impedance having a value smaller than the impedance at which the current coincides, is the largest impedance among the impedances in which the relationship between the output induced current and the conductivity of the measurement object becomes linear. The primary coil forming the primary magnetic flux ring and the secondary coil forming the secondary magnetic flux ring, and a power supply unit for applying a predetermined alternating voltage to the primary coil, and the primary coil and secondary coil for their magnetic flux ring Equipped with a measurement unit for measuring the conductivity of the measurement object from the induced current generated in the secondary coil when the measurement object forming the closed loop passes through, and a range switching unit for switching the measurement range by the measurement unit In one conductivity measuring system,
Measurement by the measuring unit, comprising an impedance circuit having a predetermined impedance passing through the primary magnetic flux ring and the secondary magnetic flux ring, and an open/close switch for switching the impedance circuit to either a closed circuit state or an open circuit state. A plurality of circuits for calibration of sensitivity for correcting sensitivity are provided so as to be switched for each measurement range,
A measurement sensitivity calculation unit that calculates measurement sensitivity based on a change in conductivity or a conductivity-related value by the measurement unit when the sensitivity calibration circuit is switched between a closed circuit state and an open circuit state;
A reference sensitivity storage unit that stores a reference sensitivity, which is a reference measurement sensitivity, for each measurement range,
A conductivity measurement system comprising a calibration unit that calibrates the measurement sensitivity of each measurement range obtained by the measurement sensitivity calculation unit to a corresponding reference sensitivity stored in the reference sensitivity storage unit. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete

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