Multiple-function fluid measuring and transmitting apparatus

• US 5,469,749 A
• Filed: 03/28/1995
• Issued: 11/28/1995
• Est. Priority Date: 09/20/1991
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamamoto, Yoshimi, Ugai, Seiichi, Shimada, Satoshi, Tobita, Tomoyuki
• Primary Examiner(s): Chilcot, Richard
• Assistant Examiner(s): PATEL, HARSHAD R
• Application Number:
  US08/411,922
• Time in Patent Office: 245 Days
• Field of Search: 73/861.02, 73/861.03, 73/861.48, 73/861.61, 73/861.63, 73/721, 73/714, 73/861.47, 374/143
• US Class Current: 73/861.47
• CPC Class Codes: G01F 1/363 with electrical or electro-mechanical indication G01F1/37 and G01F1/38 take precedence
• CPC Class Codes: G01F 1/372 with electrical or electro-mechanical indication
• CPC Class Codes: G01F 1/383 with electrical or electro-mechanical indication
• CPC Class Codes: G01F 1/44 Venturi tubes
• CPC Class Codes: G01F 23/164 using a diaphragm, bellow as transmitting element
• CPC Class Codes: G01L 19/0092 Pressure sensor associated with other sensors, e.g. for measuring acceleration or temperature G01L9/025, G01L9/045, G01L9/065, G01L9/085, G01L9/105, G01L9/125, G01L19/02, G01L19/04 take precedence; measuring two or more variable G01D21/02; temperature sensors with pressure compensation G01K1/26
• CPC Class Codes: G01L 9/0054 integral with a semiconducting diaphragm

Abstract

A measuring and controlling system is provided which has a control function as well as a measurement function to perform the measurement and control of fluid amounts such as the flow rate, pressure, liquid level, weight and so on by itself in the same field. A pressure receiving unit is directly mounted on a pipe or a container, in which a fluid under measurement exists, in order to detect the temperature, differential pressure and static pressure of the fluid under measurement independently of each other. Means for storing the characteristic of fluids under measurement is provided such that the mass flow rate, weight and liquid level can be calculated. By providing the transmitter with the measurement and control functions, the measurement and control of fluid amounts such as flow rate, pressure, liquid level, weight and so on can be performed in a closed form, thereby making it possible to simplify a correction procedure for the static pressure and temperature, improve the responsibility, and enhance the control performance of the whole plant. Also, a measuring and controlling system can be realized which reduces a wiring amount for connecting with an upper level control unit.

Claims

1. A multiple-function fluid measuring and transmitting apparatus comprising:

a conduit for flowing a fluid under measurement;

a pressure receiving portion provided in said conduit;

a seal diaphragm provided to seal said pressure receiving portion at an inner wall portion of said conduit;

a pressure receiving chamber storing a pressure/temperature communicating fluid;

a differential pressure detecting portion fixed to said conduit and having a differential pressure sensor in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for detecting a differential pressure condition of said fluid under measurement;

a temperature sensor provided at a position in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for detecting a temperature condition of said fluid under measurement;

a sensor signal output means for outputting a sensor signal from said differential pressure sensor and said temperature sensor, and;

a calculating means for receiving said sensor signal from said sensor signal output means, for performing compensation using a compensation data stored in a storing means and outputting a measurement signal for indicating a condition of said fluid under measurement.

2. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

a silicon substrate is used for said differential pressure detecting portion, and said differential pressure sensor and temperature sensor are formed of resistance elements on said silicon substrate.

3. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, further comprising:

a static pressure detecting portion having a static pressure sensor fixed at said pressure receiving chamber and being responsive to a static pressure condition of said fluid under measurement;

wherein said sensor signal output means further outputs a static pressure signal from said static pressure sensor such that said calculating means outputs said measurement signal further on a basis of said static pressure signal.

4. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 3, wherein;

a silicon monocrystalline substrate is used for said differential pressure portion and said static pressure detecting portion and said differential pressure sensor, said static pressure sensor and temperature sensor are formed of resistance elements on said silicon monocrystalline substrate.

5. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 4, wherein;

said sensor signal output means includes a multiplexer, and said multiplexer selectively send signals of said differential pressure sensor, said static pressure sensor and said temperature sensor to said calculating means.

6. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 3, wherein;

said storing means includes map data for compensating sensor outputs of said differential pressure sensor, said static pressure sensor and said temperature sensor as said compensation data.

7. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 4, wherein;

said storing means includes memory map data for compensating relationship between a temperature or static pressure and a density or compressibility factor of said fluid under measurement.

8. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said pressure receiving portion comprising a differential pressure generating means for generating a differential pressure in said fluid under measurement.

9. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 8, wherein;

said pressure receiving portion comprises an orifice as said fluid under measurement differential pressure generating means.

10. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 8, wherein;

said pressure receiving portion comprises a venturi tube as said fluid under measurement differential pressure generating means.

11. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said calculating means is provided thermally isolated from said pressure receiving portion, and receives said sensor signal from said sensor signal outputting means.

12. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said storing means stores conduit data concerning said conduit, and said calculating means outputs a flow signal indicating a flow amount of said fluid under measurement from said sensor signal with reference to said conduit data.

13. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said storing means stores fluid data concerning said fluid under measurement, and said calculating means obtains a mass flow rate of said fluid under measurement from said sensor signal referenced to said fluid data.

14. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, further comprising a display means for displaying a condition of said fluid under measurement obtained by said calculating means.

15. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said differential pressure sensor detects a differential pressure by comparing a pressure of said fluid under measurement with one of a pressure of an airtight chamber or atmospheric pressure.

16. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said storing means stores conduit data concerning said conduit, and said calculating means outputs a fluid level signal indicating a height of a fluid level of said fluid under measurement in said conduit from said sensor signal referenced to said conduit data.

17. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said storing means stores fluid data concerning said fluid under measurement, and said calculating means outputs a mass signal indicating a mass of said fluid under measurement in said conduit from said sensor signal referenced to said fluid data.

18. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said apparatus comprises a control apparatus for controlling, and transmitting and receiving control signals with respect to a plurality of other multiple-function fluid measuring and transmitting apparatuses.

19. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said multiple-function fluid measuring and transmitting apparatus controls a plurality of actuators by transmitting control signals to said plurality of actuators.

20. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein;

said multiple-function fluid measuring and transmitting apparatus carries out setting of set target value of said fluid condition from an external communication apparatus by way of wireless communication using infrared light.

21. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 1, wherein said seal diaphragm is provided on less than an entire circumferential portion of an inner wall of said conduit.

22. A compact electronic multiple-function fluid measuring and transmitting apparatus comprising:

a conduit for flowing a fluid under measurement;

a pressure receiving portion provided in said conduit;

a seal diaphragm provided to seal said pressure receiving portion at an inner wall portion of said conduit;

a pressure receiving chamber storing a pressure/temperature communicating fluid;

an electronic differential pressure detecting portion fixed to said conduit and having a differential pressure sensor in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for electronically detecting a differential pressure condition of said fluid under measurement;

an electronic temperature sensor provided at a position in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for electronically detecting a temperature condition of said fluid under measurement;

a sensor signal output means for outputting a sensor signal from said differential pressure sensor and said temperature sensor, and;

a calculating means for receiving said sensor signal from said sensor signal output means, for performing compensation using a compensation data stored in a storing means and outputting a measurement signal for indicating a condition of said fluid under measurement.

23. A multiple-function fluid measuring and transmitting apparatus as claimed in claim 22, wherein said seal diaphragm is provided on less than an entire circumferential portion of an inner wall of said conduit.

24. A compact silicon-based multiple-function fluid measuring and transmitting apparatus disposed on part of a conduit containing a major mass of a transitory working fluid so as to directly contact with said major mass of said working fluid to provide at least differential pressure measurement and temperature measurement of said working fluid in direct contact with said major mass of said working fluid said apparatus comprising:

a conduit for containing said major mass of working fluid;

a pressure receiving portion provided in said conduit;

a seal diaphragm provided to seal said pressure receiving portion at less than an entire circumferential portion of an inner wall of said conduit so as to provide a differential pressure and temperature communicating seal between said major mass of said working fluid and a pressure/temperature communicating fluid;

a pressure receiving chamber holding said pressure/temperature communicating fluid;

a differential pressure detecting portion fixed to said conduit and having a silicon-based differential pressure sensor in contact with said pressure/temperature communicating fluid for electronically detecting a differential pressure condition of said working fluid;

a silicon-based temperature sensor provided at a position in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for electronically detecting a temperature condition of said working fluid;

a sensor signal output means for outputting a sensor signal from said differential pressure sensor and said temperature sensor, and;

a calculating means for receiving said sensor signal from said sensor signal output means, for performing compensation using a compensation data stored in a storing means and outputting a measurement signal for indicating a condition of said working fluid.

25. A multiple-function fluid measuring and transmitting apparatus comprising:

a conduit for flowing a fluid under measurement;

at least one pressure receiving space adjacent a wall portion of said conduit, and connected for fluid communication with said conduit using at least one tap hole;

a seal diaphragm provided within said at least one pressure receiving space to define a pressure receiving chamber storing a pressure/temperature communicating fluid;

a differential pressure detecting portion fixed to said conduit and having a differential pressure sensor in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for detecting a differential pressure condition of said fluid under measurement;

a temperature sensor provided at a position in contact with said pressure/temperature communicating fluid at a location of said seal diaphragm for detecting a temperature condition of said fluid under measurement;

a sensor signal output means for outputting a sensor signal from said differential pressure sensor and said temperature sensor, and;

a calculating means for receiving said sensor signal from said sensor signal output means, for performing compensation using a compensation data stored in a storing means and outputting a measurement signal for indicating a condition of said fluid under measurement.

26. An apparatus as claimed in claim 25, wherein:

said at least one pressure receiving space is constituted by a first pressure receiving space adjacent a wall portion of said conduit, and connected for fluid communication with said conduit using a first tap hole, and a second pressure receiving space adjacent a wall portion of said conduit, and connected for fluid communication with said conduit using a second tap hole; and

,

said seal diaphragm is constituted by a first seal diaphragm provided within said first pressure receiving space to define a first pressure receiving chamber storing a first pressure/temperature communicating fluid, and a second seal diaphragm provided within said second pressure receiving space to define a second pressure receiving chamber storing a second pressure/temperature communicating fluid; and

said differential pressure sensor being in contact with said first pressure/temperature communicating fluid and said second pressure/temperature communicating fluid for detecting said differential pressure condition of said fluid under measurement.

27. An apparatus as claimed in claim 25, wherein;

a silicon substrate is used for said differential pressure detecting portion, and said differential pressure sensor and temperature sensor are formed of resistance elements on said silicon substrate.

28. An apparatus as claimed in claim 25, wherein said at least one tap hole is at least capillary in size.

29. An apparatus as claimed in claim 25, wherein said at least one tap hole is provided on less than an entire circumferential portion of an inner wall of said conduit.