JP2000205985A - Differential pressure transmitter with remote seal diaphragm - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reliably compensate for a zero point after assembling by arranging a means for displacing a high pressure side or low pressure side pressure receiving diaphragm by prescribed quantity by moving a high pressure side or low pressure side pressure transmitting medium. SOLUTION: A differential pressure transmitter with a remote seal diaphragm has, for example, a pressure receiving diaphragm displacing means 15. A pressure transmitting medium sealed in a high pressure side pressure receiving part and a low pressure side pressure receiving part of the differential pressure transmitter expands or contracts by an ambient temperature change, and this expansion quantity or contraction quantity is absorbed by displacement of a pressure receiving diaphragm, so that output differs. A difference in this output can be reduced by displacing a high pressure side pressure receiving diaphragm by moving, for example, a high pressure side pressure medium 13 by the pressure rceiving disphragm displacing means 15, thereby compensates for a difference in zero point output of differential pressure by an ambient temperature change. A means by a screw plug and a valve mechanism is used as the pressure receiving diaphragm displacing means 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential pressure transmitter with a remote seal diaphragm used for measuring a flow rate of a UV sterilizer, for example.

[0002]

2. Description of the Related Art As a conventional differential pressure transmitter with a remote seal diaphragm used for measuring the flow rate of a UV sterilizer, there is, for example, the one shown in FIG. The UV sterilizer 1 is composed of two tanks, an inlet-side tank 3 and an outlet-side tank 4, which are partitioned by a partition plate 2 with their lower parts connected, and a sterilizing UV lamp 5 provided on the outlet side. ing.
The water to be sterilized enters the tank 3 on the inlet side, passes through the lower part of the partition plate 2, enters the tank 4 on the outlet side, is sterilized by the UV lamp 5 for sterilization, and is discharged over the wall 6. The flow rate of the discharged treated water is determined by the differential pressure transmitter 7 with the remote seal diaphragm.
By detecting the difference in water level between the inlet-side tank 3 and the outlet-side tank 4, the differential pressure between the inlet-side hydraulic pressure and the outlet-side hydraulic pressure is detected, and this differential pressure is converted into an electric signal by a strain gauge (not shown). To measure. FIG.
FIG. 3 shows an enlarged view of the configuration of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion. A high pressure side pressure receiving portion 8 and a low pressure side pressure receiving portion 9 are formed on both end surfaces of a cylindrical member as a housing 10,
The integrated structure is optimal for detecting the difference in water level between the tank 3 on the inlet side and the tank 4 on the outlet side. The high pressure side pressure receiving section 8 includes a high pressure side pressure receiving diaphragm 11 for detecting an inlet side water pressure, and a high pressure side pressure transmission medium 13 is sealed in a liquid chamber between the high pressure side pressure receiving diaphragm 11 and the housing 10. Further, the low pressure side pressure receiving portion 9 includes a low pressure side pressure receiving diaphragm 12 for detecting an outlet side water pressure, and a low pressure side pressure transmission medium 14 is sealed in a liquid chamber between the low pressure side pressure receiving diaphragm 12 and the housing 10. . High pressure side pressure receiving diaphragm 1
The thin plate 1 and the low-pressure-side pressure-receiving diaphragm 12 are made of a thin plate of stainless steel or the like, and are formed in a waveform.

However, the above-described differential pressure transmitter with a remote seal diaphragm targets a small differential pressure region, so that
There is a problem that the two pressure transmission media 13, 14 and the like are easily affected by the ambient temperature, and this appears as a zero point error.

On the other hand, Japanese Patent Application Laid-Open No. Hei 5-223677 discloses a housing filled with a sealed liquid, a pair of seal diaphragms provided on both sides of the housing and having different expansion coefficients from the housing, and a seal diaphragm. And a silicon diaphragm having a pressure-electricity conversion element provided in the housing, and a high pressure chamber and a low pressure chamber together with a differential pressure sensor in the housing. In the differential pressure transmitter having a housing and a center diaphragm having a different expansion coefficient, the temperature characteristic is configured by making the rate of change in hardness due to temperature change substantially equal between the center diaphragm and the seal diaphragm. An improved differential pressure transmitter is disclosed.

Japanese Utility Model Laid-Open Publication No. Hei 5-2043 has a center diaphragm having a different expansion coefficient from that of a pressure receiving part and forming a waveform, and a sealed liquid chamber divided into two by the center diaphragm and a silicon diaphragm. In the differential pressure measuring device, the temperature characteristics are improved by providing a sealed liquid in which the liquid volumes of the two sealed liquid chambers are made different so as to reduce the internal pressure change due to the displacement of the center diaphragm due to the temperature change. A differential pressure measuring device is disclosed.

[0006]

However, the conventional differential pressure transmitter and the conventional differential pressure measuring device which are designed to improve the temperature characteristics make the rate of change of the hardness of the seal diaphragm substantially equal to that of the center diaphragm in advance. In advance, the filled liquid amount on the high pressure side and the low pressure side should be different in advance,
All of them are adjusted in advance at the time of assembly. For this reason, if the result is poor after assembly (after filling of the filling liquid or the like), it cannot be repaired.

[0007] The present invention has been made in view of the above,
Zero point compensation can be reliably performed after assembly, temperature error can be extremely reduced by adjusting the difference of zero point output of differential pressure due to ambient temperature change, and zero point compensation can be performed after assembly. Accordingly, it is an object of the present invention to provide a differential pressure transmitter with a remote seal diaphragm that can reduce nonstandard products generated due to manufacturing variations and reduce costs.

[0008]

According to a first aspect of the present invention, there is provided a high pressure side pressure receiving diaphragm for detecting a fluid pressure on an inlet side of a fluid to be measured, wherein a high pressure side pressure transmitting medium is sealed. A high-pressure side pressure-receiving portion, and a low-pressure side pressure-receiving portion having a low-pressure-side pressure-receiving diaphragm provided with a low-pressure-side pressure-receiving diaphragm for detecting an outlet-side fluid pressure of the fluid to be measured, on both sides of the housing, In a differential pressure transmitter with a remote seal diaphragm for measuring a flow rate of the fluid to be measured by detecting a differential pressure between a side fluid pressure and an outlet side fluid pressure, at least one of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion. And a pressure receiving diaphragm displacing means for displacing the pressure transmitting medium on the high pressure side or the low pressure side by a predetermined amount to move the pressure transmitting medium on the high pressure side or the low pressure side. With this configuration, the differential pressure transmitter with the remote seal diaphragm detects a slight differential pressure region. When the ambient temperature changes, both pressure transmitting media sealed in the high pressure side pressure receiving portion and the low pressure side pressure receiving portion expand or contract, and the rigidity of both the pressure transmitting media or the high pressure side and the low pressure side both pressure receiving diaphragms increases. If there is imbalance, the zero point output of the differential pressure shifts. By adjusting the initial position of the high-pressure side or low-pressure side pressure-receiving diaphragm variably by a predetermined amount by the pressure-receiving diaphragm displacement means, it is possible to correct the above-mentioned imbalance and suppress the deviation of the zero point output. Since the adjustment operation of the pressure receiving diaphragm displacement means is performed after assembly, reliable zero point compensation is possible.

According to a second aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the first aspect,
The gist of the present invention is that the pressure receiving diaphragm displacing means uses a screw plug that varies the internal volume of the high-pressure side or low-pressure side pressure transmitting medium enclosure according to the amount of tightening. With this configuration, the pressure receiving diaphragm is displaced in accordance with the amount of tightening of the screw plug, and the deviation of the zero point output due to a change in the ambient temperature is compensated.

According to a third aspect of the present invention, there is provided a high pressure side pressure receiving portion having a high pressure side pressure receiving diaphragm for detecting an inlet side fluid pressure of a fluid to be measured, and a high pressure side pressure transmitting medium sealed therein, and an outlet side of the fluid to be measured. A low-pressure side pressure-receiving diaphragm, which includes a low-pressure side pressure-receiving diaphragm for detecting a fluid pressure, has a low-pressure-side pressure-receiving portion in which a low-pressure-side pressure transmission medium is sealed, and detects a differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure. In the differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of the fluid to be measured, a passage communicating the high pressure side pressure transmission medium and the low pressure side pressure transmission medium is provided, and the passage is provided in the middle of the passage. The gist of the invention is to provide a valve mechanism for changing the ratio of the amount of the high-pressure side pressure transmission medium and the amount of the low-pressure side pressure transmission medium to be filled. With this configuration, the opening and closing operations of the valve mechanism adjust the imbalance of the amounts of the high-pressure side and the low-pressure side filled with the pressure transmitting medium, thereby compensating for the deviation of the zero point output of the differential pressure due to the change in the ambient temperature. You.

According to a fourth aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the third aspect,
The gist is that a needle valve is used as the valve mechanism. With this configuration, the adjustment of the imbalance of the enclosing amounts of the high-pressure side and the low-pressure side of the pressure transmission medium can be easily and reliably performed with a relatively simple configuration.

According to a fifth aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the third aspect,
The gist is that the passage is formed using a pipe outside the housing, and the valve mechanism is provided in the middle of the pipe. With this configuration, it is possible to easily adjust the imbalance of the enclosing amounts of the high-pressure side and the low-pressure side of the pressure transmitting medium from the outside after assembling the differential pressure transmitter with the remote seal diaphragm. A commercially available valve or the like can be applied to the valve mechanism.

According to a sixth aspect of the present invention, there is provided a high pressure side pressure receiving portion having a high pressure side pressure receiving diaphragm for detecting an inlet side fluid pressure of a fluid to be measured, and a high pressure side pressure transmitting medium sealed therein, and an outlet side of the fluid to be measured. An outlet-side pressure receiving portion having a low-pressure-side pressure-receiving diaphragm for detecting fluid pressure and having an outlet-side pressure-receiving portion in which a low-pressure-side pressure transmitting medium is sealed is provided on both side surfaces of the housing, and a differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure is detected. In the differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of the fluid to be measured, the pressure receiving diameter of the high pressure side or the low pressure side pressure receiving diaphragm is at least one of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion. The gist is to provide a variable pressure receiving diameter means. With this configuration, by changing the pressure receiving diameter of the high pressure side or the low pressure side pressure receiving diaphragm, the imbalance of the rigidity of both the high pressure side and the low pressure side pressure receiving diaphragm is corrected, and the deviation of the zero point output due to a change in the ambient temperature is corrected. Compensated.

According to a seventh aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the sixth aspect,
The gist of the invention is that the pressure receiving diameter variable means includes a detachable ring member that restricts a peripheral end portion of the high pressure side or the low pressure side pressure receiving diaphragm by a predetermined amount. According to this configuration, the pressure receiving diameter can be changed, specifically, by attaching and detaching a ring member to an outer peripheral portion of the pressure receiving diaphragm. The attachment and detachment of this ring member is performed after the assembly of the differential pressure transmitter with the remote seal diaphragm.

According to an eighth aspect of the present invention, there is provided a high pressure side pressure receiving portion having a high pressure side pressure receiving diaphragm for detecting an inlet side fluid pressure of a fluid to be measured, and a high pressure side pressure transmitting medium sealed therein, and an outlet side of the fluid to be measured. A low-pressure side pressure-receiving diaphragm, which includes a low-pressure side pressure-receiving diaphragm for detecting a fluid pressure, has a low-pressure-side pressure-receiving portion in which a low-pressure-side pressure transmission medium is sealed, and detects a differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure. In the differential pressure transmitter with the remote seal diaphragm for measuring the flow rate of the fluid to be measured, the high pressure between the high pressure side pressure receiving portion and the atmosphere and the low pressure side pressure receiving portion inside and the atmosphere. The gist is that elastic members are provided to absorb the internal pressure change amounts of the side pressure receiving portion and the low pressure side pressure receiving portion, respectively, and the rigidity of the elastic members is varied. With this configuration,
By varying the rigidity of the elastic member, the rigidity of the high-pressure side and low-pressure side pressure receiving diaphragms is equivalently varied, the imbalance in the rigidity of both pressure receiving diaphragms is corrected, and the zero point output due to the ambient temperature change is corrected. The deviation is compensated.

According to a ninth aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the eighth aspect,
The gist of the present invention is that a bellows is used as the elastic member, and the bellows is configured to vary the rigidity of the bellows in response to a leaf spring having a variable rigidity. With this configuration, the stiffness of the bellows as an elastic member can be changed by adjusting the stiffness of the leaf spring after assembling the differential pressure transmitter with the remote seal diaphragm.

According to a tenth aspect of the present invention, in the differential pressure transmitter with the remote seal diaphragm according to the eighth aspect, a diaphragm is used as the elastic member, and the diaphragm is acted on by a leaf spring having a variable rigidity. The gist of the present invention is that the stiffness is varied. With this configuration, the rigidity of the diaphragm as the elastic member can be changed by adjusting the rigidity of the leaf spring after assembling the differential pressure transmitter with the remote seal diaphragm.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 and FIG. 2 are diagrams showing a first embodiment of the present invention. In FIGS. 1 and the drawings showing the respective embodiments described later, the same or equivalent members as those in FIGS. 11 and 12 are denoted by the same reference numerals as those described above, and redundant description will be omitted.

FIG. 1 shows the structure of a pressure receiving diaphragm displacement means in a differential pressure transmitter with a remote seal diaphragm. In this embodiment, a pressure-receiving diaphragm displacement means for moving a high-pressure side or a low-pressure side pressure transmission medium to at least one of a high-pressure side pressure-receiving portion and a low-pressure side pressure-receiving portion to displace a high-pressure side or a low-pressure side pressure-receiving diaphragm by a predetermined amount. Fifteen
Is provided. This pressure receiving diaphragm displacement means 15
Thus, the initial position of the high-pressure side or low-pressure side pressure receiving diaphragm is variably adjusted by a predetermined amount, thereby compensating for the deviation amount of the zero point output of the differential pressure due to a change in the ambient temperature. The mechanism will be described with reference to FIG. In general, as shown in the equation (1), the relationship between the applied pressure (differential pressure) ΔP and the moving volume ΔV has a third-order relationship.
The rigidity changes depending on the position.

ΔP = A · ΔV + B · ΔV ³ (1) The pressure transmission medium sealed in the high pressure side pressure receiving portion and the low pressure side pressure receiving portion expands or contracts due to a change in ambient temperature.
The expansion or contraction is absorbed by the displacement of the pressure receiving diaphragm. At this time, the pressure applied to the pressure transmitting medium changes according to the rigidity of the pressure receiving diaphragm. For example, assuming that the rigidity of the high-pressure side and the low-pressure side pressure-receiving diaphragms is the same, if the amount _VH of the high-pressure side pressure transmitting medium is larger than the amount _VL of the low-pressure side pressure transmitting medium, the ambient temperature increases. Both the high-pressure side pressure transmission medium and the low-pressure side pressure transmission medium expand, but the expansion of the high pressure-side pressure transmission medium _VH and the rigidity of the high-pressure side pressure-receiving diaphragm cause the expansion of the high-pressure side pressure-receiving diaphragm. The generated pressure increases, and the output shifts to the positive side. Therefore, in this case, the high pressure side pressure receiving diaphragm is depressed by the high pressure side pressure receiving diaphragm displacing means 15 so that the rigidity when expanded can be made smaller than that of the low pressure side pressure receiving diaphragm. The shift of the output to the positive side due to the large amount of sealing can be reduced. On the other hand, when the filling amount V _L of the low-pressure side pressure transmitting medium is larger than the filling amount V _H of the high-pressure side pressure transmitting medium, the deviation of the differential pressure output to the negative side is reduced by expanding the high pressure side pressure receiving diaphragm. can do. Since the adjusting operation of the pressure receiving diaphragm displacement means 15 can be performed after assembling the differential pressure transmitter with the remote seal diaphragm, reliable zero point compensation can be performed. Pressure receiving diaphragm displacement means 15
May be provided on any one of the high pressure side and the low pressure side, and may be provided on both the high pressure side and the low pressure side.

FIG. 3 shows a second embodiment of the present invention. This embodiment corresponds to a specific example of the pressure receiving diaphragm displacement means 15 in the first embodiment. That is, in the present embodiment, as the pressure receiving diaphragm displacement means 15, a screw plug 16 that varies the internal volume of the high pressure side or low pressure side pressure transmission medium enclosure according to the amount of tightening is used.
Is used. By tightening the screw plug 16,
The pressure receiving diaphragm can be displaced by the amount by which the screw plug 16 has moved. The pressure transmission medium 13 includes an O-ring 17 provided between the screw plug 16 and the housing 10.
Sealed by.

FIG. 4 shows a third embodiment of the present invention. In the present embodiment, a passage 18 is provided for communicating the high pressure side pressure transmission medium 13 and the low pressure side pressure transmission medium 14, and the high pressure side pressure transmission medium 13 and the low pressure side pressure transmission medium 14 are sealed in the passage 18. A valve mechanism 19 for changing the ratio of the amount is provided. As described in the first embodiment, the difference between the sealed amount of the high-pressure side pressure transmitting medium and the sealed amount of the low-pressure side pressure transmitting medium causes a shift amount at the zero point of the differential pressure output. By adjusting the difference of the sealed pressure transmitting medium amount calculated from the amount by opening and closing the valve mechanism 19, the deviation amount of the differential pressure output can be reduced. For example, when the pressure transmission medium encapsulation amount is larger on the low pressure side than on the high pressure side, the amount is obtained from the difference in the differential pressure output, and the differential pressure for moving this amount to the low pressure side is obtained.
What is necessary is just to open the valve mechanism 19 in a state where this differential pressure is applied to the pressure receiving portion, and close it in an equilibrium state.

FIG. 5 shows a fourth embodiment of the present invention. This embodiment corresponds to a specific example of the valve mechanism 19 according to the third embodiment. That is, in the present embodiment, the needle valve 20 is used as the valve mechanism 19. The pressure transmission media 13 and 14 are
The housing is sealed by an O-ring 21 provided between the housing and the housing 10. By rotating the screw in the needle valve 20, the passages 18 on the high-pressure side and the low-pressure side are opened and closed, and the ratio of the sealed amount of the high-pressure side pressure transmission medium 13 and the low-pressure side pressure transmission medium 14 is changed. In the present embodiment, the valve mechanism 19 can be realized with a relatively simple configuration.

FIG. 6 shows a fifth embodiment of the present invention. This embodiment corresponds to another specific example of the valve mechanism 19 in the third embodiment. That is, in the present embodiment, a pipe 22 for communicating the high-pressure side pressure transmission medium 13 and the low-pressure side pressure transmission medium 14 is provided outside the housing 10, and a valve 23 as a valve mechanism is provided in the middle of the pipe 22. It is provided. With such a configuration, the adjustment of the imbalance of the enclosing amounts of the high-pressure side pressure transmission medium 13 and the low-pressure side pressure transmission medium 14 is easily performed from the outside after the differential pressure transmitter with the remote seal diaphragm is assembled. be able to. In addition, a commercially available valve can be applied to the valve 23, and a configuration having high reliability against external leakage can be provided.

FIG. 7 shows a sixth embodiment of the present invention. In each of the above embodiments, the amount of sealing between the high pressure side pressure transmission medium 13 and the low pressure side pressure transmission medium 14 is moved to adjust the amount of difference in differential pressure output due to a change in ambient temperature. Transmission medium 13 and low pressure side pressure transmission medium 14
In the present embodiment, the rigidity of the pressure receiving diaphragm is adjusted by changing the pressure receiving diameter of the high pressure side or low pressure side pressure receiving diaphragm by the pressure receiving diameter variable means. . The following relationship exists between the rigidity A with respect to the pressure-movement volume of the pressure receiving diaphragm and the pressure receiving diameter d.

A∝1 / d ⁶ (2) That is, the rigidity A increases as the pressure receiving diameter d decreases. For example, when the zero point output shifts to the positive side due to a change in the ambient temperature, the shift amount of the zero point output can be reduced by reducing the effective diameter of the low pressure side pressure receiving diaphragm.

FIG. 7 shows a specific embodiment of the pressure receiving diameter varying means. A ring member 24 that restrains the outer peripheral portion of the pressure receiving diaphragm 11 by a predetermined amount is detachably attached to the outer peripheral portion of the pressure receiving diaphragm 11. The ring member 24 is a peripheral end portion φ of the pressure receiving diaphragm 11.
_In order to always contact _d , the pressure receiving diaphragm 11 is kept swelling outward within the operating ambient temperature. The ring member 24 may be provided on either the high-pressure side or the low-pressure side, or may be provided on both the high-pressure side and the low-pressure side.

FIG. 8 shows a seventh embodiment of the present invention. In the present embodiment, the elastic members 25, 26 capable of varying the rigidity between the inside of the pressure receiving portion on both the high pressure side and the low pressure side and the atmosphere.
Is provided. The elastic members 25 and 26 are displaced by a differential pressure between the internal pressure and the atmospheric pressure, and function to absorb the internal pressure. By changing the stiffness of the elastic members 25 and 26, the stiffness of the high-pressure side and the low-pressure side pressure receiving diaphragms is equivalently changed, and the deviation of the zero point output can be reduced by balancing the internal pressure change amount caused by the temperature change.

FIG. 9 shows an eighth embodiment of the present invention. This embodiment corresponds to a specific example of the seventh embodiment. The bellows 27 is used as an elastic member, and the rigidity of the bellows 27 can be adjusted by a leaf spring 29 connected by a connecting rod 28. 31 is a welding part. For example, when the zero point output shifts to the positive side with respect to a change in ambient temperature, the rigidity of the low-pressure side leaf spring is increased, or the high-pressure side leaf spring is thinned to reduce the rigidity of the entire elastic member. By doing so, the shift of the zero point can be reduced.

FIG. 10 shows a ninth embodiment of the present invention. This embodiment corresponds to another specific example of the seventh embodiment. The diaphragm 30 is used as an elastic member, and the rigidity can be changed by a leaf spring 29 connected by a connecting rod 28. The operation is the same as in the eighth embodiment.

[0032]

As described above, according to the first aspect of the present invention, the high pressure side or the low pressure side pressure transmission medium is moved to at least one of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion, and the high pressure side or the low pressure side pressure transmitting medium is moved. Since the pressure-receiving diaphragm displacement means for displacing the pressure-receiving diaphragm on the low-pressure side by a predetermined amount is provided, the initial position of the pressure-receiving diaphragm on the high-pressure side or the low-pressure side is variably adjusted by a predetermined amount, thereby enclosing both the high-pressure side and the low-pressure side pressure transmission medium. Even if there is an imbalance in the amount or rigidity of both high-pressure and low-pressure receiving diaphragms, this imbalance is corrected and the deviation of the zero point output of the differential pressure due to the change in the ambient temperature can be suppressed, and the temperature error can be reduced. It can be extremely small. Adjustment of the pressure-receiving diaphragm displacement means is performed after assembling the differential pressure transmitter with the remote seal diaphragm, so reliable zero point compensation can be performed, and non-standard products caused by manufacturing variations can be reduced. Cost can be reduced.

According to the second aspect of the present invention, since the pressure receiving diaphragm displacing means uses a screw plug that changes the internal volume of the high-pressure side or low-pressure side pressure transmission medium enclosure in accordance with the amount of tightening, After assembling the differential pressure transmitter with the remote seal diaphragm, the deviation of the zero point output due to the change in the ambient temperature can be easily and surely compensated only by adjusting the tightening amount of the screw plug.

According to the third aspect of the present invention, a passage for communicating the high pressure side pressure transmission medium and the low pressure side pressure transmission medium is provided, and the high pressure side pressure transmission medium and the low pressure side pressure transmission medium are provided in the passage. Since the valve mechanism that changes the ratio of the amount of sealing is provided, after opening and closing the valve mechanism after assembling the differential pressure transmitter with the remote seal diaphragm, the high pressure side and the low pressure side are sealed. The amount of imbalance can be adjusted, and the deviation of the zero point output of the differential pressure due to a change in the ambient temperature can be compensated.

According to the fourth aspect of the present invention, since a needle valve is used as the valve mechanism, it is possible to adjust the imbalance of the enclosing amounts of the high-pressure side and the low-pressure side pressure transmitting medium by a relatively simple configuration. Can be easily and reliably performed.

According to the fifth aspect of the present invention, since the passage is formed using a pipe outside the housing, and the valve mechanism is provided in the middle of the pipe, both the high pressure side and the low pressure side pressure transmission medium are provided. Adjustment of the imbalance of the amount of
After assembling the differential pressure transmitter with the remote seal diaphragm, it can be easily performed from the outside. Further, an appropriate valve mechanism such as a commercially available valve can be selected for the valve mechanism.

According to the sixth aspect of the present invention, at least one of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion is provided with the pressure receiving diameter variable means for varying the pressure receiving diameter of the high pressure side or the low pressure side pressure receiving diaphragm. Therefore, it is possible to correct the imbalance of the rigidity of the two pressure receiving diaphragms on the low pressure side, and to compensate for the deviation of the zero point output of the differential pressure due to a change in the ambient temperature.

According to the seventh aspect of the present invention, a detachable ring member for restricting a peripheral end of the high-pressure side or the low-pressure side pressure-receiving diaphragm by a predetermined amount is used as the pressure-receiving diameter variable means. By attaching and detaching the ring member to the outer peripheral portion of the pressure receiving diaphragm after assembling the differential pressure transmitter, it is possible to correct the imbalance in rigidity between the high pressure side and the low pressure side.

According to the eighth aspect of the present invention, the amount of change in the internal pressure of the high-pressure side pressure-receiving part and the low-pressure side pressure-receiving part between the inside of the high-pressure side pressure-receiving part and the atmosphere and between the inside of the low-pressure side pressure-receiving part and the atmosphere. Since the elastic members for absorbing the pressure are provided and the rigidity of the elastic member is varied, the rigidity of the pressure receiving diaphragm on the high pressure side and the low pressure side can be equivalently varied,
The unbalance of the rigidity of the two pressure receiving diaphragms can be corrected, and the deviation of the zero point output of the differential pressure due to a change in the ambient temperature can be compensated.

According to the ninth aspect of the present invention, a bellows is used as the elastic member, and the bellows is configured to vary the rigidity of the bellows in response to a leaf spring having a variable rigidity. After assembling the differential pressure transmitter, it is possible to vary the rigidity of the bellows as an elastic member by adjusting the rigidity of the leaf spring, and equivalently vary the rigidity of the high-pressure side and the low-pressure side pressure receiving diaphragm. Can be.

According to the tenth aspect of the present invention, a diaphragm is used as the elastic member, and the diaphragm is adapted to respond to a leaf spring having a variable rigidity to vary the rigidity of the diaphragm. After assembling the differential pressure transmitter, the rigidity of the diaphragm as an elastic member can be varied by adjusting the rigidity of the leaf spring, and equivalently, the rigidity of the high-pressure side and the low-pressure side pressure-receiving diaphragm can be varied. Can be.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of a pressure receiving diaphragm displacement means in a differential pressure transmitter with a remote seal diaphragm according to a first embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a moving volume ΔV of a pressure receiving diaphragm and an applied pressure ΔP in the first embodiment.

FIG. 3 is a configuration diagram of a pressure receiving diaphragm displacement unit according to a second embodiment of the present invention.

FIG. 4 is a configuration diagram of a passage and a valve mechanism according to a third embodiment of the present invention.

FIG. 5 is a configuration diagram of a needle valve portion according to a fourth embodiment of the present invention.

FIG. 6 is a configuration diagram of a pipe and a valve part according to a fifth embodiment of the present invention.

FIG. 7 is a configuration diagram of a ring member as pressure receiving diameter varying means according to a sixth embodiment of the present invention.

FIG. 8 is a configuration diagram of a portion where an elastic member is provided according to a seventh embodiment of the present invention.

FIG. 9 is a configuration diagram of an arrangement portion of a bellows and a leaf spring according to an eighth embodiment of the present invention.

FIG. 10 is a configuration diagram of an arrangement portion of a diaphragm and a leaf spring according to a ninth embodiment of the present invention.

FIG. 11 is a diagram showing the overall configuration of a conventional differential pressure transmitter with a remote seal diaphragm installed in a UV sterilizer.

FIG. 12 is an enlarged sectional view showing a configuration of a high-pressure side / low-pressure side pressure receiving portion in the conventional example.

[Explanation of symbols]

 Reference Signs List 8 High pressure side pressure receiving part 9 Low pressure side pressure receiving part 10 Housing 11 High pressure side pressure receiving diaphragm 12 Low pressure side pressure receiving diaphragm 13 High pressure side pressure transmission medium 14 Low pressure side pressure transmission medium 15 Pressure receiving diaphragm displacement means 16 Screw plug 18 Passage 19 Valve mechanism 20 Needle valve Reference Signs List 22 pipe 23 valve 24 ring member (pressure receiving diameter variable means) 25, 26 elastic member 27 bellows 29 leaf spring 30 diaphragm

Claims (10)

[Claims] 1. A high pressure side pressure receiving section having a high pressure side pressure receiving diaphragm for detecting an inlet side fluid pressure of a fluid to be measured and a high pressure side pressure transmitting medium sealed therein, and a low pressure detecting portion for detecting an outlet side fluid pressure of the fluid to be measured. A low-pressure-side pressure-receiving portion in which a low-pressure-side pressure transmission medium is sealed and provided on both sides of the housing, and the differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure is detected to detect the fluid to be measured. In a differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of
At least one of the high pressure side pressure receiving part and the low pressure side pressure receiving part is provided with a pressure receiving diaphragm displacement means for moving the high pressure side or the low pressure side pressure transmitting medium to displace the high pressure side or the low pressure side pressure receiving diaphragm by a predetermined amount. A differential pressure transmitter with a remote seal diaphragm. 2. As the pressure receiving diaphragm displacement means,
2. The differential pressure transmitter with a remote seal diaphragm according to claim 1, wherein a screw plug that changes the internal volume of the high-pressure side or low-pressure side pressure transmission medium enclosure portion according to a tightening amount is used. 3. A high pressure side pressure receiving section having a high pressure side pressure receiving diaphragm for detecting a fluid pressure on the inlet side of a fluid to be measured, and a high pressure side pressure receiving medium filled with a high pressure side pressure transmitting medium, and a low pressure for detecting an outlet side fluid pressure of the fluid to be measured. A low-pressure-side pressure-receiving portion in which a low-pressure-side pressure transmission medium is sealed and provided on both sides of the housing, and the differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure is detected to detect the fluid to be measured. In a differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of
A valve mechanism for providing a passage communicating the high-pressure side pressure transmission medium and the low-pressure side pressure transmission medium, and a valve mechanism for changing a ratio of a sealed amount of the high-pressure side pressure transmission medium and the low-pressure side pressure transmission medium in the middle of this passage; A differential pressure transmitter with a remote seal diaphragm, which is provided. 4. The differential pressure transmitter with a remote seal diaphragm according to claim 3, wherein a needle valve is used as said valve mechanism. 5. The differential pressure transmitter with a remote seal diaphragm according to claim 3, wherein the passage is formed using a pipe outside the housing, and the valve mechanism is provided in the middle of the pipe. . 6. A high pressure side pressure receiving portion having a high pressure side pressure receiving diaphragm for detecting an inlet side fluid pressure of a fluid to be measured and a high pressure side pressure transmitting medium sealed therein, and a low pressure detecting portion for detecting an outlet side fluid pressure of the fluid to be measured. An outlet-side pressure receiving portion having a side-side pressure-receiving diaphragm and a low-pressure-side pressure transmitting medium sealed on both sides of the housing, and detecting the differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure to detect the fluid to be measured. In a differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of
A differential pressure transmitter with a remote seal diaphragm, characterized in that at least one of the high pressure side pressure receiving part and the low pressure side pressure receiving part is provided with pressure receiving diameter variable means for varying the pressure receiving diameter of the high pressure side or low pressure side pressure receiving diaphragm. . 7. A remote control according to claim 6, wherein said pressure receiving diameter variable means comprises a detachable ring member for restraining a peripheral end portion of said high pressure side or said low pressure side pressure receiving diaphragm by a predetermined amount. Differential pressure transmitter with seal diaphragm. 8. A high-pressure side pressure receiving section having a high-pressure side pressure-receiving diaphragm for detecting an inlet-side fluid pressure of a fluid to be measured and a high-pressure side pressure transmitting medium sealed therein, and a low-pressure side for detecting an outlet-side fluid pressure of the fluid to be measured. A low-pressure-side pressure-receiving portion in which a low-pressure-side pressure transmission medium is sealed and provided on both sides of the housing, and the differential pressure between the inlet-side fluid pressure and the outlet-side fluid pressure is detected to detect the fluid to be measured. In a differential pressure transmitter with a remote seal diaphragm for measuring the flow rate of
Between the inside of the high pressure side pressure receiving portion and the atmosphere and between the inside of the low pressure side pressure receiving portion and the atmosphere, an elastic member for absorbing the internal pressure change amount of the high pressure side pressure receiving portion and the low pressure side pressure receiving portion is provided, respectively.
A differential pressure transmitter with a remote seal diaphragm, characterized in that the rigidity of the elastic member is variable. 9. The remote control according to claim 8, wherein a bellows is used as said elastic member, and said bellows is adapted to vary a rigidity of said bellows in response to a leaf spring having a variable rigidity. Differential pressure transmitter with seal diaphragm. 10. The remote according to claim 8, wherein a diaphragm is used as the elastic member, and the diaphragm is adapted to change the rigidity of the diaphragm by responding to a leaf spring having a variable rigidity. Differential pressure transmitter with seal diaphragm.