JPH0926348A - Immersion pressure type water gauge - Google Patents

Abstract

PROBLEM TO BE SOLVED: To surely measure a specified water level by using a general electric wire having a simple configuration, while reducing the cost, widening the condition applicability, and improving the intermediate connection and workability. SOLUTION: A water gauge main body 1, which is connected to the end part of a general electric wire 2 and immersible in water, a diaphragm 4 which is provided at the bottom of the water gauge main body 1 and constitute a differential pressure measurement part measuring differential pressure between reference pressure Poo and water pressure Pw caused by sealing fluid, and the first amplifier 5, are provided. And, an atmospheric pressure sensor 8 provided separately from the water gauge main body 1, and a second amplifier 7 acting as an output part, which finds differential pressure between the differential pressure (Pw-Poo) measured at the differential pressure measurement part and atmospheric pressure Po detected by the atmospheric pressure sensor 8 and transduces the differential pressure into an electric value for output, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pouring pressure type water level gauge.

[0002]

2. Description of the Related Art Conventionally, an injection pressure type water level gauge of this type having a structure as shown in FIG. 2 has been used.
In FIG. 2, reference numeral 20 denotes a water level gauge main body, which is integrally connected to one end of a long resin cable 21 so as to be thrown into water. At the bottom of this water gauge main body 21,
For example, a water pressure introduction port 22 such as a recess opening downward is formed, and atmospheric pressure is introduced into the upper chamber partitioned by the diaphragm 23 through the hollow cable 24 inserted and held in the resin cable 21. And, the lower part is configured so that water pressure acts.

Reference numeral 25 is a first amplifier installed in the main body 20 of the water level gauge, which displaces the differential pressure (Pw-Po) between the atmospheric pressure Po and the water pressure Pw introduced through the hollow cable 24 into the diaphragm 23. The quantity is measured, amplified, and transmitted through a wire 26 to a control panel (not shown) or the like. Reference numeral 27 is a second amplifier mounted on the control panel or the like, which converts the differential pressure (Pw-Po) sent through the electric wire 26 into a current value I and outputs the current value I. The output current value I
The conversion formula is as follows: I = f · (Pw−Po) Here, f is a conversion coefficient from the differential pressure to the current value.

[0004]

In the conventional pouring pressure type water level gauge having the above-mentioned structure, a large space is provided between the water level gauge body 20 and the second amplifier 27 in the upper compartment by the diaphragm 23. A hollow cable 24 and electric wire 26, which are open to the atmosphere for introducing atmospheric pressure, are inserted inside, a shield is provided on the outer circumference, and the hollow cable 24 is reinforced so as not to be crushed when an external force is applied. Since it is necessary to stretch and use a long resin cable 21, the cost is likely to be high, and it is impossible or extremely difficult to change the length by the intermediate connection of the cable 21 itself. In addition, it is not possible to deal with when the cable length is insufficient, and lacks applicability to the location conditions of the installation site. In addition, the allowable radius of curvature of the resin cable 21 is restricted to a radius that does not cause a failure in the atmospheric pressure introducing operation due to the blockage of the hollow cable 24 inserted through the resin cable 21, and therefore, there is a large constraint condition in terms of construction.

Therefore, the invention according to claim 1 of the present invention has been made in view of the above-mentioned circumstances, and it is possible to use a general-purpose electric wire having a simple structure, to reduce the cost and to apply the condition by the intermediate connection. It is an object of the present invention to provide an injection pressure type water level gauge capable of reliably measuring a predetermined water level while expanding the property and improving the workability. Also,
In addition to the object of the invention described in claim 1, the invention described in claim 2 aims at providing an injection pressure type water level gauge capable of accurately measuring a predetermined water level regardless of a change in water temperature. .

[0006]

In order to achieve the above-mentioned object, the casting pressure type water level gauge according to the invention of claim 1 in the present invention is connected to one end of a cable and thrown into water. The main body of the level gauge, the differential pressure measuring section that is provided at the bottom of the main body of the water level gauge and measures the differential pressure between the reference pressure and the water pressure due to the enclosed fluid, and the main body of the water level gauge are provided separately. An atmospheric pressure sensor, an output for obtaining a differential pressure between the differential pressure measured by the differential pressure measuring unit and the atmospheric pressure detected by the atmospheric pressure sensor, and converting the differential pressure into an electric value for output. And a section. Here, as a cable that allows the water level meter body to be thrown into water, a general-purpose electric wire formed by coating the outer periphery of a conductor with a resin layer having corrosion resistance, weather resistance, and electrical insulation may be used alone, Further, a thin resin tube may be fitted onto the electric wire. The reference pressure is obtained by enclosing a gas such as air or nitrogen gas in the closed space.

In addition, the pouring pressure type water level gauge according to the invention of claim 2 is the same as that of the invention of claim 1, but is installed in the water level gauge main body near the differential pressure measuring part to measure the measured differential pressure. A temperature compensation sensor for correction is added. here,
The temperature compensation sensor measures the temperature of the water in which the water level meter is thrown to obtain the difference from the standard temperature, and the pressure conversion value corresponding to the value of the temperature difference is used to correct the differential pressure between the reference pressure and water pressure. To use.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a schematic sectional view of an injection pressure type water level gauge according to the present invention.
Is the main body of the water level gauge, which is a long cable, specifically the conductor 2a
The outer periphery of the resin layer 2b having corrosion resistance, weather resistance, and electrical insulation
It is integrally connected to one end of the general-purpose electric wire 2 which is covered with, and can be thrown into water. A water pressure introducing port 3 such as a recess opening downward is formed at the bottom of the water level gauge main body 1, and the pressure in the upper chamber 4A, which is partitioned by the diaphragm 4 and sealed, is a reference pressure due to pressurization of air. The pressure is set to Poo, and water pressure acts on the lower portion of the diaphragm 4.

Reference numeral 5 denotes a first unit installed in the main body 1 of the water level gauge.
The amplifier constitutes a differential pressure measuring unit together with the diaphragm 4, and the differential pressure (Pw-Poo) between the reference pressure Poo and the water pressure Pw is measured as the displacement amount of the diaphragm 4 and amplified to be amplified by the general-purpose electric wire 2 Through the control panel (not shown). 6 is the above-mentioned first as a differential pressure measuring unit
It is a temperature compensation sensor installed in the water level meter main body 1 near the amplifier 5, measures the temperature of the water into which the water level meter main body 1 is thrown, obtains a difference from a preset standard temperature, and the temperature difference The pressure conversion value corresponding to the value of
Is input to correct the differential pressure between the reference pressure Poo and the water pressure Pw due to the water temperature.

Reference numeral 7 is a second amplifier as an output unit mounted on the control panel or the like, and 8 is an atmospheric pressure sensor provided separately from the water level gauge body 1 and installed near the control panel or the like. And the atmospheric pressure P measured by this sensor 8
o and the differential pressure (Pw-
Poo) is input to the second amplifier 7, where the differential pressure between the differential pressure (Pw-Poo) sent through the electric wire 2 and the atmospheric pressure Po is obtained, and the differential pressure is converted into a current value I. Convert and output. The conversion formula of the output current value I is I = f · (Pw-Poo-Po).

In the pouring pressure type water level gauge constructed as described above, it is one of the constituent elements of the differential pressure measuring section and is the upper compartment 4 of the diaphragm 4 which is positioned in the water by throwing.
It becomes possible to omit the use of a hollow cable for introducing atmospheric pressure into A, and a general-purpose electric wire 2 having a very simple structure is stretched between the water gauge main body 1 and the second amplifier 7. Just get better. Therefore, the cost can be reduced with the use of the general-purpose electric wire 2, and the intermediate connection can be easily performed by using the existing connection fittings. Therefore, the cable length of the water level gauge can be easily changed. Correspondingly, it is possible to expand the applicability to location conditions such as installation location. Further, since the allowable radius of curvature can be made sufficiently large by using the general-purpose electric wire 2, there is no malfunction, so that there are no constraint conditions for construction and the construction efficiency can be improved.

[0012]

As described above, according to the first aspect of the invention, a general-purpose electric wire having a simple structure is used alone, or a simple cable having a thin resin tube covering the outside of the general-purpose electric wire is used. This makes it possible to reliably measure a predetermined water level while reducing the cost, expanding the applicability of conditions by the intermediate connection, and improving the workability. Further, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1, there is an effect that a predetermined water level can be measured very accurately when used under any water temperature condition. .

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of an injection pressure type water level gauge which is an embodiment of the present invention.

FIG. 2 is a schematic sectional view of a conventional pouring pressure type water level gauge.

[Explanation of symbols]

 1 Water level gauge main body 2 General-purpose electric wire (cable) 4 Diaphragm (differential pressure measuring section) 5 First amplifier (differential pressure measuring section) 6 Temperature compensation sensor 7 Second amplifier (output section) 8 Atmospheric pressure sensor

Claims (2)

[Claims] 1. A differential pressure measuring unit for measuring a differential pressure between a reference pressure and a hydraulic pressure by a sealed fluid is provided at the bottom of a water level gauge main body which is connected to one end of a cable and can be thrown into water. An atmospheric pressure sensor is provided separately from the main body of the water level gauge, and the differential pressure between the differential pressure measured by the differential pressure measuring unit and the atmospheric pressure detected by the atmospheric pressure sensor is obtained, and the differential pressure is an electric value. An injection pressure type water level gauge provided with an output section for converting to and outputting. 2. In the main body of the water gauge near the differential pressure measuring section,
The pouring pressure type water level gauge according to claim 1, further comprising a temperature compensation sensor for correcting the temperature of the measured differential pressure.