JP2015219103A - Immersion type water level gauge calibration system, calibration method thereof, calibration program thereof, and immersion type water level gauge with calibration function - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an immersion type water level gauge calibration technique capable of acquiring the density of a stored liquid from a distance and calibrating the indicated value of water level in accordance with this density.SOLUTION: A calibration system 10 comprises: a first measurement device, secured to the outer surface of a detector 24, for measuring the water pressure, as a first measured water pressure, that a detector 24 receives; a second measurement device 60, secured to the outer surface of the detector 24 at a different depth of water than the secured first measurement device 50, for measuring pressure in the depth of water as a second measured water pressure; a derivation unit 47 for deriving the density of a liquid on the basis of a difference L in water depth between the second measurement device 60 and the first measurement device 50 and the first and second measured water pressures; and a correction unit 44 for correcting the indicated value of water level on the basis of the density derived by the derivation unit 47.

Description

  The present invention relates to a technique for calibrating an indicated value of a throwing water level meter.

  In facilities that have become difficult to enter, such as nuclear power plants damaged by tsunamis and earthquakes, it is sometimes required to measure the water level of the liquid inside. As a conventionally known water level meter, there is a bubble type water level meter that calculates a water level by measuring a pressure required to send bubbles to the bottom of the water with a bubbler tube having an end portion disposed on the bottom of the water.

  The bubble-type water level meter is a water level meter that slowly blows out bubbles from a tube opened in a liquid and measures the pressure in the tube at that time with a sensor. Since the pressure in the pipe is equal to the sum of the atmospheric pressure and the water pressure applied to the open end of the pipe, the water level can be obtained by subtracting the atmospheric pressure from the pressure at the open end.

  The bubble-type water level meter requires an air supply source for sending bubbles to the bottom of the water, and the apparatus becomes large. In addition, installation work for fixing the device in the vicinity of the liquid is required.

One type of water level gauge that does not require such installation work is the throw-in type water level gauge. The throw-in type water level meter is smaller and easier to operate than the bubble type water level meter. This throwing water level gauge is widely used in general industries to measure water levels in river monitoring programs and water and sewage systems.
In addition, a throw-in water level meter that is easier to set up and maintain and that can measure a stable water level has been proposed.

Japanese Patent Application Laid-Open No. 07-054394 JP 2000-337945 A Japanese Utility Model Publication No. 3-2821

However, in the conventional technique described above, the indicated value of the water level displayed on the display unit is based on the water pressure of the detector, and may not completely match the actual water level.
For example, if the density of the liquid increases depending on the type of liquid stored, the water level is displayed as deeper than the actual level.

Therefore, if it is attempted to calibrate the water level indication value in consideration of the density, it is necessary to work at the site for a certain period of time in order to obtain the density of the stored liquid.
However, since the stored liquid is radioactively contaminated water, there has been a problem that workers are exposed by obtaining this density.

  The present invention has been made in consideration of such circumstances, and is a throw-in type water level meter capable of remotely acquiring the density of the stored liquid and calibrating the indicated value of the water level according to this density. An object of the present invention is to provide a calibration system, a calibration method thereof, a calibration program thereof, and an input water level meter with a calibration function.

  The calibration system of the throw-in type water level meter according to the present embodiment seals the inside of a housing partly opened in the liquid with a pressure sensor, the water pressure received by the pressure sensor from the liquid and the housing A throw-in type comprising: a detector that detects a differential pressure with respect to the atmospheric pressure received from the inside by a connected hollow cable; and a display unit that displays a liquid level based on the water pressure and the differential pressure between the atmospheric pressure. In a calibration system for calibrating an indication value of the water level displayed on the display unit with respect to a water level gauge, the water pressure received by the detector fixed to the outer surface of the detector is measured as a first measurement water pressure. A first measuring device, a second measuring device fixed to the outer surface of the detector at a different water depth from the fixed first measuring device, and measuring the pressure at the water depth as a second measuring water pressure; and the second measuring device. With the first measuring instrument A derivation unit for deriving the density of the liquid based on the difference in water depth, the first measurement water pressure and the second measurement water pressure, and correction of the indicated value of the water level based on the density derived by the derivation unit And a correction unit that performs the following.

  The throwing water level meter with a calibration function according to the present embodiment has a pressure sensor that seals the inside of a housing that is partially opened in the liquid, and the water pressure that the pressure sensor receives from the liquid and the housing. A detector that detects a differential pressure with respect to the atmospheric pressure received from the inside by a hollow cable connected to the body, a display unit that displays a liquid level based on the differential pressure, and an outer surface of the detector A first measuring device for measuring the water pressure received by the detector as a first measuring water pressure, and a pressure at the water depth fixed to the outer surface of the detector at a water depth different from the first measuring device to be fixed. The density of the liquid is derived based on the difference in water depth between the second measuring device that measures the two measuring water pressures and the first measuring device of the second measuring device, the first measuring water pressure, and the second measuring water pressure. And a derivation unit derived from the derivation unit. In which and a correcting unit for correcting the indicated value of the water level on the basis of the density.

  In addition, the method for calibrating the throw-in type water level meter according to the present embodiment seals the inside of a housing partly opened in the liquid with a pressure sensor, and the water pressure received by the pressure sensor from the liquid and the housing A detector that detects a differential pressure with respect to the atmospheric pressure received from the inside by a hollow cable connected to the body, and a display unit that displays a water level of the liquid based on the water pressure and the differential pressure of the atmospheric pressure. In a calibration method for calibrating an indication value of the water level displayed on the display unit with respect to a built-in water level gauge, the water pressure received by the detector by a first measuring device fixed to the outer surface of the detector is measured. Measuring as a first measured water pressure, measuring a pressure at the water depth as a second measured water pressure by a second measuring device fixed to the outer surface of the detector at a different water depth from the fixed first measuring device; The second A step of deriving the density of the liquid based on the difference in water depth from the first measuring device of the measuring device, the first measured water pressure and the second measured water pressure, and the water level based on the derived density A step of correcting the indicated value.

  In addition, the calibration program for the throw-in type water level meter according to the present embodiment seals the inside of a housing partially opened in the liquid with a pressure sensor, and the water pressure received by the pressure sensor from the liquid and the housing A detector that detects a differential pressure with respect to the atmospheric pressure received from the inside by a hollow cable connected to the body, and a display unit that displays a water level of the liquid based on the water pressure and the differential pressure of the atmospheric pressure. In a calibration method for calibrating an indication value of the water level displayed on the display unit with respect to a built-in water level gauge, the detector receives the computer by a first measuring device fixed to the outer surface of the detector. Measuring the water pressure as a first measurement water pressure, measuring the pressure at the water depth as a second measurement water pressure by a second measuring device fixed to the outer surface of the detector at a different water depth from the fixed first measuring device; A step of deriving a density of the liquid based on the difference in water depth of the second measuring device from the first measuring device, the first measured water pressure and the second measured water pressure, and the derived density. A step of correcting the indicated value of the water level on the basis thereof.

  INDUSTRIAL APPLICABILITY According to the present invention, it is possible to remotely acquire the density of the stored liquid and calibrate the indicated value of the water level according to this density, the calibration system of the throwing water level gauge, the calibration method thereof, and the calibration program thereof And an input water level gauge with a calibration function.

The schematic block diagram of the calibration system of the throwing-type water level meter of the throwing-type water level meter concerning 1st Embodiment. FIG. 3 is a schematic cross-sectional view of a detector included in the throwing water level meter to which the calibration system for the throwing water level meter is applied. In 1st Embodiment, the schematic block diagram which shows the throwing type water level meter when the calibration system of the throwing type water level meter is not connected. The figure which shows the correspondence of the differential pressure | voltage of each pressure concerning a reference | standard pressure side diaphragm and a water pressure side diaphragm, and the indication value of a water level. The block diagram of the repeater designed according to the calibration system of the throw-in type water level meter concerning 1st Embodiment. The flowchart explaining the calibration method concerning 1st Embodiment. Schematic configuration diagram of a calibration system for an input water level meter according to the second embodiment Explanatory drawing of the calibration method (zero point correction | amendment) of the throw-in type water level meter concerning 2nd Embodiment. The schematic block diagram of the modification of the calibration system of the throw-in type water level meter concerning 2nd Embodiment. Explanatory drawing of the adjustment in the calibration method (span adjustment) of the throw-in type water level meter concerning 2nd Embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

(First embodiment)
FIG. 1 is a schematic configuration diagram of a calibration system 10 (hereinafter simply referred to as “calibration system 10”) for an input water level meter according to the first embodiment.
FIG. 2 is a schematic cross-sectional view of the detector 24 provided in the throwing water level meter 20 to which the calibration system 10 is applied.

As shown in FIG. 1 and FIG. 2, the calibration system 10 according to the first embodiment seals the inside of a housing 21 partially opened in a liquid with a pressure sensor 22. a detector 24 for detecting the differential pressure ΔP between the atmospheric pressure P _atm to receive from within the pressure P _w and the hollow cable 23 connected to the housing 21 to receive the liquid, the differential pressure ΔP of the pressure P _w and atmospheric pressure P _atm In the calibration system 10 that calibrates the indicated value of the water level displayed on the display unit 26 with respect to the pouring water level meter 20 having the display unit 26 that displays the liquid level based on the a first measuring instrument 50 for measuring the pressure P _w which is fixed to the front detector 24 receives a first measurement pressure P _s1, secured to the outer surface of the detector 24 in the first measuring instrument 50 fixed different depths Second pressure measurement at the water depth A second measuring device 60 which measures a Teisuiatsu _{P s2,} difference L of water depth between the first measuring instrument 50 of the second measuring device 60, the liquid on the basis of the first measurement pressure _{P s1} and the second measuring water pressure _{P s2} A derivation unit 47 for deriving the density σ, and a correction unit 44 for correcting Ψ of the indicated value of the water level based on the density σ derived by the derivation unit 47.

  The calibration system 10 further fixes the air opening hole 15 that opens the hollow cable 23 to the atmosphere, the signal line hole 14 that fixes the signal line 38 that transmits the differential pressure ΔP in the form of an electrical signal, and the first bubbler tube 51. A repeater 13 having a second back pressure hole 17 for fixing the first back pressure hole 16 and the second bubbler tube 61 is provided.

FIG. 3 is a schematic configuration diagram showing an example of the throw-in type water level meter 20 when the calibration system 10 is not connected in the first embodiment.
First, the throw-in type water level meter 20 targeted by the calibration system 10 will be described with reference to FIGS. 2 and 3.

  The detector 24 constituting the throw-in water level gauge 20 is thrown into the liquid for measuring the water level, and sinks to the bottom surface of the structure storing the liquid. As shown in FIG. 2, the detector 24 has a cylindrical outer shape, for example, by a casing 21 in which a water inlet 33 is provided on one bottom surface.

Inside the housing 21, a pressure sensor 22 is installed in the vicinity of the bottom surface where the water inlet 33 is provided so as to seal the housing 21.
By the pressure sensor 22, the inside of the housing 21 is isolated from the surrounding liquid, and the liquid does not enter further from the pressure sensor 22.

On the other hand, the hollow cable 23 is connected to the other bottom surface where the water inlet 33 is not provided. The hollow cable 23 is normally open to the atmosphere at the other end to which the casing 21 is not connected, and maintains the inside of the casing 21 at the atmospheric pressure _Patm . One surface of the pressure sensor 22 facing the inside of the sealed casing 21 receives the atmospheric pressure _Patm via the hollow cable 23.

On the other hand, the other surface in contact with the liquid in the pressure sensor 22 undergoes a pressure P _w. For example, a pressure sensor 22 using a diaphragm 25 is widely used.
The diaphragm is an elastic diaphragm, and the degree of expansion and dent of the diaphragm due to pressure is read.

  There are various methods for reading, and there are cases where reading is performed by connecting to a Bourdon tube gauge filled with oil, and the deformation is read mechanically, optically or electrically. As an electrical reading method, there are a semiconductor strain gage type in which strain is sensed by a piezoelectric element installed in the diaphragm 25 or a capacitance type in which displacement is sensed.

Incidentally, describes 2, the water pressure side diaphragm 25a which receives the water pressure P _w, and the reference pressure side diaphragm 25b which receives the atmospheric pressure P _atm from the hollow cable 23, the pressure sensor 22 having as an example.
Hereinafter, the pressure sensor 22 will be described on the assumption that a piezoelectric element is provided in each of the two diaphragms 25 and a difference between voltages generated in the piezoelectric elements is read by the difference unit 35.

  The voltage difference read by the difference unit 35 is transmitted to the V / I conversion circuit 37 as a differential pressure ΔP of the pressure received by the water pressure side diaphragm 25a and the reference pressure side diaphragm 25b. The V / I conversion circuit 37 converts this voltage difference into a current signal and outputs it to the signal line 38. The signal line 38 is covered with the covering material 28 together with the hollow cable 23 and the reinforcing wire 18, and is connected to the conversion unit 32 (FIG. 1).

In addition, this conversion part 32 is often installed in the place away from the structure where the liquid was stored, as FIG. 3 shows.
Since most of the water level gauges 20 to which the calibration system 10 or the water level gauge calibration method (hereinafter simply referred to as “calibration method”) according to the first embodiment is applied are used for radiation-contaminated water. It is.
The conversion unit 32 performs I / V conversion again on the received current signal and transmits it to the display unit 26 installed in the central control room 41, for example.

Here, FIG. 4 is a diagram showing a correspondence relationship between the pressure difference ΔP of each pressure applied to the reference pressure side diaphragm 25b and the water pressure side diaphragm 25a and the water level indication value displayed on the display unit 26.
The display unit 26 displays an electric signal based on the differential pressure ΔP transmitted from the conversion unit 32 (FIG. 2) as the liquid water level (36.4 m in FIG. 4).

However, indication of the water level described above, because it is intended to be calculated on the basis of the pressure P _w, there may not completely the actual water level match.
For example, when the density σ of the liquid increases depending on the type of stored liquid, the water level is displayed as deeper than the actual level.
The calibration system 10 and the calibration method according to the first embodiment calibrate the indication value of the water level on the display unit 26.

Next, returning to FIG. 1, various members included in the calibration system 10 will be described (refer to FIGS. 2 and 4 as appropriate).
The first measuring device 50 measures the water pressure P _w which is fixed to the outer surface of the detector 24 is a detector 24 receives as a first measurement pressure P _s1. For example, the first measuring instrument 50 measures the first back pressure P _s1 by pressurizing the first bubbler tube 51 whose opening end 27a is fixed to the outer surface of the detector 24 and the first bubbler tube 51. A first measurement unit 52.
At this time, the first measured water pressure P _s1 is the first back pressure P _s1 .

  The first bubbler tube 51 is a tube made of silicon, metal, or the like with an open end 27 a fixed to the outer surface of the detector 24. When the first bubbler tube 51 is additionally fixed to the ready-made detector 24, the covering material 28 is further wrapped with the wrapping material 19 as shown in FIG. That's fine.

  The other free end of the first bubbler tube 51 that opens into the atmosphere is connected to the first measurement unit 52 of the first measurement unit 52 installed in the vicinity of the conversion unit 32.

  The first measuring unit 52 applies a back pressure to the first bubbler tube 51 until a bubble leaks from the opening end 27 a of the first bubbler tube 51.

The first measuring unit 52 increases the back pressure and transmits the back pressure at the limit at which bubbles are generated from the opening end 27a to the applying unit 46 as the first back pressure _Ps1 . Applying unit 46 the value received in the first back pressure P _s1 is normally applies the first back pressure P _s1 from the hollow cable 23 open to the atmosphere.

The second measuring device 60 is fixed to the outer surface of the detector 24 at a different water depth from the fixed first measuring device 50, and measures the pressure at the water depth as the second measured water pressure _Ps2 .
The second measuring device 60 can be the same type as the first measuring device 50.
That is, the second measuring device 60 includes, for example, a second bubbler tube 61 in which the opening end 27b is fixed to the outer surface of the detector 24 at a different water depth from the opening end 27a of the first bubbler tube 51, and the second bubbler tube 61. And a second measuring unit 62 that measures the second back pressure _Ps2 by pressurizing the second back pressure _Ps2 .
At this time, the second measuring water pressure _{P s2} becomes second back pressure _{P s2.}

Similarly to the first bubbler tube 51, the second bubbler tube 61 is wound together with, for example, the wrapping material 19 and becomes a single wire 29.
By being fixed in this manner, a constant difference in water depth L occurs between the opening end 27b of the second bubbler tube 61 and the opening end 27a of the first bubbler tube 51.

The deriving unit 47 determines the density σ of the liquid _expressed by Equation (1) based on the difference L in water depth between the second measuring device 60 and the first measuring device 50, the first measured water pressure P _s1 and the second measured water pressure P _s2. Is derived.
σ = (| P _s1 −P _s2 | / g) / L (1)
However, g represents a gravitational acceleration.
The density σ derived in this way is displayed on the display unit 26.

Based on the density σ derived by the derivation unit 47, the correction unit 44 performs the correction Ψ shown by the equation (2) of the water level instruction value.
D = (ΔP / g) / σ (2)
However, D represents the true water depth of the hydraulic side diaphragm 25a.

For example, as shown in FIG. 4, the worker reflects the liquid density σ on the water level instruction value with the water level correction button 44 a (44) of the display unit 26 (35.0 m in FIG. 4).
The correction Ψ can be automatically performed by directly connecting the derivation unit 47 and the correction unit 44.
The correction unit 44 also corrects the electrical signal related to P _w of the conversion unit 32 may be directly corrected to the display unit 26.

  By the way, FIG. 5 is a block diagram of the repeater 13 designed according to the calibration system 10 according to the first embodiment. As described above, the electrical signal of the differential pressure ΔP is transmitted to the conversion unit 32 through the signal line 38.

  However, since most of the water level gauges 20 (FIG. 3) to which the calibration system 10 is applied are applied to radiation-contaminated water, the water level is managed remotely. Therefore, it is assumed that the signal line 38 is extended by the extension signal line 38a and connected to the conversion unit 32 installed away from the structure storing the radiation contaminated water.

  The free end of the signal line 38 (FIG. 2) is fixed by being passed through the signal line hole 14 having the connector 14a of the repeater 13 at least at a place where an operator can enter for a short time, such as a liquid inlet.

Further, the first bubbler tube 51 needs to be connected to the first measurement unit 52 in order to acquire the value of the first back pressure P _s1 . Therefore, the first back pressure hole 16 is provided in the repeater 13 to fix the first bubbler tube 51.
Furthermore, by providing the connector 16a in the first back pressure hole 16, the first bubbler tube 51 is easily connected to the first measurement unit 52 via the first extension tube 51a.

Similarly, a second back pressure hole 17 that fixes the second bubbler tube 61 and facilitates connection to the second measuring unit 62 and its connector 17a are also provided.
Similarly to the first bubbler tube 51, the second bubbler tube 61 is also connected to the second measuring unit 62 via the second extension tube 61a.

Note that any of the connectors (14a, 16a, 17a) does not have to be a single component as shown in FIG. 6, and may be integrated with each connection hole (14, 16, 17).
Thus, by providing the repeater 13 including the signal line hole 14, the first back pressure hole 16, and the second back pressure hole 17, the calibration system 10 can be connected in a short time during calibration. That is, the exposure of workers can be minimized.

  The repeater 13 may be provided with an air release hole 15 in order to fix the hollow cable 23 and stably release the air.

  Next, a calibration method according to the first embodiment will be described with reference to the flowchart of FIG. 6 (refer to FIGS. 1 to 4 as appropriate).

  The target water level gauge 20 has a detector 24 sinking to the bottom of a structure storing a liquid whose water level is detected. A first bubbler tube 51 and a second bubbler tube 61 are installed in the detector 24 with the opening end 27a or the opening end 27b fixed to the outer surface of the detector 24, respectively. The other free ends of the first bubbler tube 51 and the second bubbler tube 61 are connected to the repeater 13. Further, the hollow cable 23 is open to the atmosphere in the open air hole 15 of the repeater 13.

  On the other hand, the signal line 38 is connected to the conversion unit 32 by the extension signal line 38 a even when not calibrating, and transmits the detected electric signal of the differential pressure ΔP to the conversion unit 32. The electrical signal received by the conversion unit 32 is sent to the display unit 26 installed in the central control room 41 or the like, and is monitored by the worker as the water level.

First, the calibration system 10 is connected to such an input water level gauge 20 (S11).
Specifically, first, the worker connects the first extension tube 51 a to the first back pressure hole 16 of the repeater 13, and connects the first bubbler tube 51 and the first measurement unit 52.
Similarly, the second extension tube 61 a is connected to the second back pressure hole 17, and the second bubbler tube 61 and the second measurement unit 62 are connected.

At the same time, the correction unit 44 is connected to the conversion unit 32 and the display unit 26.
Note that when the correction Ψ is performed by the water level correction button 44 a of the display unit 26, the correction unit 44 may not be connected to the conversion unit 32.

Next, the 1st measurement part 52 applies to the 1st bubbler tube 51 (S12).
And the pressure when a bubble leaks from the opening end 27a is measured as 1st back pressure _Ps1 (S13).

Similarly, it is applied to the second bubbler tube 61 by the second measuring unit 62 (S14).
And the pressure at the time of a bubble leaking from the opening end 27b is measured as 2nd back pressure _Ps2 (S15).

Next, the derivation unit 47 derives the liquid density σ based on the difference L in water depth between the second measuring device 60 and the first measuring device 50, the first measured water pressure P _s1 and the second measured water pressure P _s2 ( S16).
Then, the correcting unit 44 corrects the indication value of the water level based on the density σ derived by the deriving unit 47 (S17).

  As described above, according to the calibration system 10 and the calibration method according to the first embodiment, the density σ of the stored liquid is obtained remotely, and the indication value of the water level is calibrated according to the density σ. Can do.

  In addition, the calibration system 10 mentioned above can be integrated with the throw-in type water level meter 20, and it can also be set as the water level meter 40 with a calibration function as a whole.

(Second Embodiment)
FIG. 7 is a schematic configuration diagram of the calibration system 10 according to the second embodiment.
As shown in FIG. 7, the calibration system 10 according to the second embodiment obtains the first measurement water pressure P _s1 from the hollow cable 23 based on the value of the first measurement water pressure P _s1 transmitted from the first measuring device 50. An application unit 46 for applying is provided.

Deviation of the indicated value of the water level, in addition to those due to the density σ of the liquid, is also caused by the deviation of the response ratio of the indicated value to changes in displacement and pressure P _w of the zero point of the indicated value.
Therefore, when the indicated value of the water level is strictly calibrated, it is preferable to perform the zero adjustment and the span adjustment for adjusting the response ratio of the indicated value together with the correction Ψ by the density σ shown in the first embodiment.

Therefore, the application unit 46 is connected to the first measuring device 50, and the first measurement water pressure P _s1 is applied from the application unit 46 to the hollow cable 23.
As in the first embodiment, a first bubbler tube 51 and a first measurement unit 52 can be used for the first measuring instrument 50.

An extension hollow cable 23a (23) is installed in the atmosphere opening hole 15, and a reference pressure switching valve 31 of a three-way valve is installed at the other end of the extension hollow cable 23a.
At the time of calibration, the reference pressure switching valve 31 is switched from the atmosphere release side to the application side to which the application unit 46 is connected.
The first back pressure P _s1 measured by the first measurement unit 52 is applied from the hollow cable 23 to the inside of the detector 24 by the application unit 46.

Here, FIG. 8 is an explanatory view of the calibration method (zero point correction) of the throwing water level meter according to the second embodiment.
The inside of the detector 24 rises from the atmospheric pressure P _atm to the first back pressure P _s1 by application from the application unit 46.

When you are the depth of the open end 27a is matched with depth of water pressure side diaphragm 25a of the first Baburachubu 51, first back pressure _{P s1} is consistent with pressure _{P w.}
Therefore, if the instruction value is not deviated, the instruction value at this time should be zero.

If the instruction value at this time is not zero, the worker adjusts the instruction value so as to become the zero point from the zero point correction button 44b (44) of the display unit 26, for example.
Correction unit 44 which has received the information from the zero point correction button 44b corrects the electrical signal related to pressure P _w of the conversion unit 32.
Further, as in the first embodiment, the correction Ψ may be directly performed on the display unit 26.

FIG. 9 is a schematic configuration diagram showing a modification of the calibration system 10 according to the second embodiment.
FIG. 10 is an explanatory diagram of a modified example (span adjustment) of the calibration method according to the second embodiment.

In the case of adjusting the span, the calibration system 10 adds the water pressure from the atmospheric pressure P _atm to the detector 24 via the hollow cable 23 as shown in FIGS. 9 and 10 in addition to the configuration in the case of zero point correction. An index pressure adding section 34 that applies a plurality of index pressures P _c (P _{c1 to} P _c5 ) up to P _w, and a differential pressure ΔP between the index pressure P _c and the measured water pressure P _s connected to the index pressure adding section 34. and a reference pressure gauge 36 for detecting _c .

The index pressure adding unit 34 applies a plurality of index pressures P _c from the atmospheric pressure P _atm to the water pressure P _w to the detector 24.
For example, as shown in FIG. 9, the index pressure adding unit 34 is a pressurizing pump 34 a (34) to which a reference pressure gauge 36 is connected.

The aforementioned reference pressure switching valve 31 installed in the extension hollow cable 23a is a three-way valve or the like.
At the time of calibration, the application portion 46 is connected to one of the two connection holes of the reference pressure switching valve 31, and the other is opened to the atmosphere, so that the reference pressure applied to the reference pressure side diaphragm 25b is switched as appropriate.

  When performing span adjustment, a three-way valve span switching valve 42 is connected to the connection hole on the atmosphere opening side. An index pressure adding unit 34 is connected to the span switching valve 42 together with a reference pressure gauge 36.

One of the two connection holes of the reference pressure switching valve 31 is connected to the application unit 46 and the other is opened to the atmosphere, so that the reference pressure applied to the reference pressure side diaphragm 25b is appropriately switched.
When performing span adjustment, a three-way valve span switching valve 42 is connected to the connection hole on the atmosphere opening side.
An index pressure adding unit 34 is connected to the span switching valve 42 together with a reference pressure gauge 36.

As shown in FIG. 10, the reference pressure gauge 36 converts the value of the differential pressure ΔP _c between the index pressure P _c applied by the index pressure adding unit 34 and the first back pressure or the differential pressure ΔP _c into a water level. Display the value.
The value of the reference pressure gauge 36 is regarded as accurate, and when the indicated value on the display unit 26 deviates from the display on the reference pressure gauge 36, the indicated value on the display unit 26 is adjusted Θ.

Adjustment Θ of the display unit 26 is manually performed from the span adjustment button 44c (44) while an operator of the central control room 41 visually recognizes the reference pressure gauge 36.
Note that the reference pressure gauge 36 may be connected to the conversion unit 32, and the correction unit 44 connected to the conversion unit 32 may automatically adjust Θ.

Except for performing zero point correction or span adjustment, the second embodiment has the same structure and operation procedure as those of the first embodiment, and a duplicate description will be omitted.
Also in the drawings, portions having a common configuration or function are denoted by the same reference numerals, and redundant description is omitted.

  As described above, according to the calibration system 10 according to the second embodiment, in addition to the effects of the first embodiment, it is possible to perform more precise calibration of the indicated value such as zero point correction and span adjustment.

According to the calibration system 10 of at least one embodiment described above, the density σ of the stored liquid is remotely controlled by the first measured water pressure P _s1 and the second measured water pressure P _s2 measured at two points having different depths. It is possible to acquire and calibrate the indicated value of the water level according to the density σ.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, changes, and combinations can be made without departing from the scope of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  For example, in each embodiment, the liquid whose water level is detected is described as being limited to radioactively contaminated water, but the present invention is not limited to radioactively contaminated water.

DESCRIPTION OF SYMBOLS 10 ... Calibration system (calibration system) of throw-in type water level gauge, 13 ... Repeater, 14 (14a) ... Signal wire hole (connector), 15 ... Air release hole, 16 (16a) ... 1st back pressure hole, Connector) 17 (17a) ... second back pressure hole (connector), 18 ... strengthening wire, 19 ... wrapping material, 20 ... impregnated water level gauge, 21 ... housing, 22 ... pressure sensor, 23 (23a) ... Hollow cable (extension hollow cable), 24 ... Detector, 25 (25a, 25b) ... Diaphragm (hydraulic pressure side diaphragm, reference pressure side diaphragm), 26 ... Display section, 27a ... Opening end of first bubbler tube, 27b ... Second Open end of bubbler tube, 28 ... covering material, 29 ... wire, 31 ... reference pressure switching valve, 32 ... conversion unit, 33 ... water inlet, 34 (34a) ... index pressure adding unit (pressure pump), 35 ... Difference unit, 36 ... reference pressure gauge, 37 ... V / I conversion circuit, 38 (38a) ... signal line (extension signal line), 40 ... water level meter with calibration function, 41 ... central control room, 42 ... span switching valve, 44 (44a, 44b, 44c) ... correction unit ( Water level correction button, zero point correction button, span adjustment button), 46... Application unit, 47 .. derivation unit, 50 (51, 52)... First measurement device (first bubbler tube, first measurement unit), 51a (51 ) ... 1st extension tube, 60 (61, 62) ... 2nd measuring device (2nd bubbler tube, 2nd measurement part), 61a (61) ... 2nd extension tube, L ... Difference in water depth, _Patm ... Large Atmospheric pressure, P _c ... Indicator pressure, P _s (P _s1 , P _s2 ) ... Measured water pressure (first measured water pressure (first back pressure), second measured water pressure (second back pressure)), P _w ... water pressure, ΔP ... differential pressure, ΔP _c ... differential pressure, Θ ... adjustment, Ψ ... correction, σ ... density.

Claims (11)

The inside of the housing partly opened in the liquid is sealed with a pressure sensor, and the difference between the water pressure received by the pressure sensor from the liquid and the atmospheric pressure received from the inside by the hollow cable connected to the housing A detector for detecting pressure;
A calibration system that calibrates the indicated value of the water level displayed on the display unit with respect to a throwing-type water level meter having a display unit that displays the water level of the liquid based on the water pressure and the differential pressure between the atmospheric pressures In
A first measuring device that measures the water pressure received by the detector fixed to the outer surface of the detector as a first measuring water pressure;
A second measuring device fixed to the outer surface of the detector at a different water depth from the first measuring device to be fixed, and measuring a pressure at the water depth as a second measured water pressure;
A derivation unit for deriving the density of the liquid based on the difference in water depth of the second measuring device from the first measuring device, the first measured water pressure, and the second measured water pressure;
A correction unit that corrects the indicated value of the water level based on the density derived by the deriving unit; The first measuring device includes:
A first bubbler tube having an open end fixed to the outer surface of the detector;
A first measuring unit that pressurizes the first bubbler tube and measures a first back pressure;
The first measured water pressure is the first back pressure,
The second measuring device includes:
A second bubbler tube having an open end fixed to the outer surface of the detector at a different water depth from the open end of the first bubbler tube;
A second measuring unit that pressurizes the second bubbler tube to measure a second back pressure, and
The calibration system for an input water level gauge according to claim 1, wherein the second measured water pressure is the second back pressure. 2. A reference pressure switching valve that is installed in the hollow cable and switches the pressure applied to the detector via the hollow cable from the atmospheric pressure to the first measured water pressure. 2. The calibration system for the throwing water level meter according to 2. An index pressure adding unit that applies a plurality of index pressures from the atmospheric pressure to the water pressure to the detector via the hollow cable;
4. The throwing type according to claim 2, further comprising a reference pressure gauge connected to the index pressure adding unit and detecting a differential pressure between the index pressure and the first measured water pressure. Calibration system for water level gauge. The index pressure adding unit is a pressure pump,
5. A span switching valve that is connected to the reference pressure switching valve and switches the pressure applied to the inside of the detector from the atmospheric pressure to the index pressure from the pressure pump. Calibration system for water level gauges. The inside of the housing partly opened in the liquid is sealed with a pressure sensor, and the difference between the water pressure received by the pressure sensor from the liquid and the atmospheric pressure received from the inside by the hollow cable connected to the housing A detector for detecting pressure;
A display unit for displaying the liquid level based on the differential pressure;
A first measuring device that measures the water pressure received by the detector fixed to the outer surface of the detector as a first measuring water pressure;
A second measuring device fixed to the outer surface of the detector at a different water depth from the first measuring device to be fixed, and measuring a pressure at the water depth as a second measured water pressure;
A derivation unit for deriving the density of the liquid based on the difference in water depth of the second measuring device from the first measuring device, the first measured water pressure, and the second measured water pressure;
And a correction unit that corrects the indicated value of the water level based on the density derived by the deriving unit. The first measuring device includes:
A first bubbler tube having an open end fixed to the outer surface of the detector;
A first measuring unit that pressurizes the first bubbler tube and measures a first back pressure;
The first measured water pressure is the first back pressure,
The second measuring device includes:
A second bubbler tube having an open end fixed to the outer surface of the detector at a different water depth from the open end of the first bubbler tube;
A second measuring unit that pressurizes the second bubbler tube to measure a second back pressure, and
The throwing water level meter with a calibration function according to claim 6, wherein the second measured water pressure is the second back pressure. A relay having a signal line hole for fixing a signal line for transmitting the differential pressure in the form of an electric signal, a first back pressure hole for fixing the first bubbler tube, and a second back pressure hole for fixing the second bubbler tube. The throwing water level meter with a calibration function according to claim 7, further comprising a vessel. The pressure sensor seals an end of the opened casing and receives the water pressure in the liquid, and is connected to the casing by being disposed inside the sealed casing The injection type water level meter with a calibration function according to any one of claims 6 to 8, further comprising a reference pressure side diaphragm that receives atmospheric pressure from the hollow cable. The inside of the housing partly opened in the liquid is sealed with a pressure sensor, and the difference between the water pressure received by the pressure sensor from the liquid and the atmospheric pressure received from the inside by the hollow cable connected to the housing A detector for detecting pressure;
A calibration method for calibrating the indicated value of the water level displayed on the display unit with respect to a throwing-type water level meter having a display unit that displays the water level of the liquid based on the water pressure and the differential pressure between the atmospheric pressure In
Measuring the water pressure received by the detector as a first measuring water pressure by a first measuring device fixed to the outer surface of the detector;
Measuring the pressure at the water depth as a second measurement water pressure by a second measuring device fixed to the outer surface of the detector at a different water depth from the first measuring device to be fixed;
Deriving the density of the liquid based on the difference in water depth of the second measuring device from the first measuring device, the first measured water pressure and the second measured water pressure;
And correcting the indicated value of the water level based on the derived density. The inside of the housing partly opened in the liquid is sealed with a pressure sensor, and the difference between the water pressure received by the pressure sensor from the liquid and the atmospheric pressure received from the inside by the hollow cable connected to the housing A detector for detecting pressure;
A calibration method for calibrating the indicated value of the water level displayed on the display unit with respect to a throwing-type water level meter having a display unit that displays the water level of the liquid based on the water pressure and the differential pressure between the atmospheric pressure In
On the computer,
Measuring the water pressure received by the detector as a first measuring water pressure by a first measuring device fixed to the outer surface of the detector;
Measuring the pressure at the water depth as a second measured water pressure by a second measuring device fixed to the outer surface of the detector at a different water depth from the fixed first measuring device;
Deriving the density of the liquid based on the difference in water depth of the second measuring device from the first measuring device, the first measured water pressure and the second measured water pressure;
A calibration program for a throw-in type water level meter, comprising: executing a step of correcting the indicated value of the water level based on the derived density.

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