GB1515611A - Electric circuits - Google Patents

Electric circuits

Info

Publication number
GB1515611A
GB1515611A GB979276A GB979276A GB1515611A GB 1515611 A GB1515611 A GB 1515611A GB 979276 A GB979276 A GB 979276A GB 979276 A GB979276 A GB 979276A GB 1515611 A GB1515611 A GB 1515611A
Authority
GB
United Kingdom
Prior art keywords
resistors
current
network
bridge
resistor
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB979276A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Emerson Process Management Ltd
Original Assignee
Rosemount Engineering Co Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Rosemount Engineering Co Ltd filed Critical Rosemount Engineering Co Ltd
Priority to GB979276A priority Critical patent/GB1515611A/en
Priority to DE19772710473 priority patent/DE2710473A1/en
Publication of GB1515611A publication Critical patent/GB1515611A/en
Expired legal-status Critical Current

Links

Classifications

    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/696—Circuits therefor, e.g. constant-current flow meters
    • G01F1/698—Feedback or rebalancing circuits, e.g. self heated constant temperature flowmeters
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F1/00—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow
    • G01F1/68—Measuring the volume flow or mass flow of fluid or fluent solid material wherein the fluid passes through a meter in a continuous flow by using thermal effects
    • G01F1/684—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow
    • G01F1/6842—Structural arrangements; Mounting of elements, e.g. in relation to fluid flow with means for influencing the fluid flow
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01K—MEASURING TEMPERATURE; MEASURING QUANTITY OF HEAT; THERMALLY-SENSITIVE ELEMENTS NOT OTHERWISE PROVIDED FOR
    • G01K7/00—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements
    • G01K7/16—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements
    • G01K7/22—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor
    • G01K7/24—Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat ; Power supply therefor, e.g. using thermoelectric elements using resistive elements the element being a non-linear resistance, e.g. thermistor in a specially-adapted circuit, e.g. bridge circuit
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N27/00—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means
    • G01N27/02—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance
    • G01N27/04—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance
    • G01N27/14—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature
    • G01N27/18—Investigating or analysing materials by the use of electric, electrochemical, or magnetic means by investigating impedance by investigating resistance of an electrically-heated body in dependence upon change of temperature caused by changes in the thermal conductivity of a surrounding material to be tested
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01P—MEASURING LINEAR OR ANGULAR SPEED, ACCELERATION, DECELERATION, OR SHOCK; INDICATING PRESENCE, ABSENCE, OR DIRECTION, OF MOVEMENT
    • G01P5/00—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft
    • G01P5/10—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables
    • G01P5/12—Measuring speed of fluids, e.g. of air stream; Measuring speed of bodies relative to fluids, e.g. of ship, of aircraft by measuring thermal variables using variation of resistance of a heated conductor

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Chemical & Material Sciences (AREA)
  • Fluid Mechanics (AREA)
  • Electrochemistry (AREA)
  • Analytical Chemistry (AREA)
  • Aviation & Aerospace Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Nonlinear Science (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Investigating Or Analyzing Materials Using Thermal Means (AREA)
  • Investigating Or Analyzing Materials By The Use Of Electric Means (AREA)
  • Measuring Volume Flow (AREA)

Abstract

1515611 Measuring heat flow electrically ROSEMOUNT ENG CO Ltd 2 March 1977 [11 March 1976] 09792/76 Headings G1A and G1N Three similar temperature-sensitive resistors 1, 2, 3, Fig. 2, are incorporated in a D.C. bridge network whose unbalance voltage, amplified at 11, determines the bridge current required to balance the network by appropriate heating of resistors 1-3. The resistors 9, 10 which complete the bridge are such that the resistor 9 has a value slightly greater than twice that of resistor 10. The amplified unbalance current i flows substantially wholly through resistors 1-3, heating resistor 3 in proportion to i<SP>2</SP> and resistors 1, 2 in proportion to (i/2)<SP>2</SP>, and the value of the current i is automatically controlled to produce a balanced condition in the network. If the resistors 1-3 are subsequently subjected to a heat change, the current taken by the network, predominantly that taken by the bridge, is proportional to the parameter causing the heat change. For use as a flowmeter the resistors 1-3, formed as platinum films on an alumina substrate, are mounted on one face of a Venturi constriction 4, Fig. lb, in a duct 8 carrying a fluid. The current taken by the network, indicated on meter 21, is shown to be proportional the fluid flow-rate. In another embodiment the resistors 1-3 are suspended in a gas to measure its thermal conductivity. An additional resistor 22 is introduced into the bridge circuit and the resistance values selected as described to make the measured current independent of ambient temperature. The apparatus may be used as a vacuum gauge or to determine the concentration of a particular component in a gas mixture. The resistors 1-3 may be mounted on a steel probe 24, Fig. 3, for insertion in e.g. soil or food to monitor a characteristic of the tested material. For use as a radiation pyrometer, the radiant heat is shielded either from resistors 1, 2 or from 3 and the measured current is indicative of the temperature of the radiation source. The radiation may alternatively be an infrared beam, possibly passing through materials having different absorption characteristics.
GB979276A 1976-03-11 1976-03-11 Electric circuits Expired GB1515611A (en)

Priority Applications (2)

Application Number Priority Date Filing Date Title
GB979276A GB1515611A (en) 1976-03-11 1976-03-11 Electric circuits
DE19772710473 DE2710473A1 (en) 1976-03-11 1977-03-10 CIRCUIT ARRANGEMENT FOR DETERMINING THE SPEED OF HEAT LOSS

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB979276A GB1515611A (en) 1976-03-11 1976-03-11 Electric circuits

Publications (1)

Publication Number Publication Date
GB1515611A true GB1515611A (en) 1978-06-28

Family

ID=9878854

Family Applications (1)

Application Number Title Priority Date Filing Date
GB979276A Expired GB1515611A (en) 1976-03-11 1976-03-11 Electric circuits

Country Status (2)

Country Link
DE (1) DE2710473A1 (en)
GB (1) GB1515611A (en)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3130817A1 (en) * 1981-08-04 1983-02-24 Leybold-Heraeus GmbH, 5000 Köln HEATING PIPE VACUUM METER
DE19617238A1 (en) * 1996-04-30 1997-11-06 Leybold Vakuum Gmbh Circuit for temperature compensation of a thermal conduction vacuum meter
DE102006027420A1 (en) * 2006-06-13 2007-12-27 Siemens Ag Hot film anemometer for air mass measurement of airflow in internal combustion engine, has sensor units embedded in flow-type body such that side of units directed against direction of air flow is protected from contamination due to airflow
FR2930640A1 (en) * 2008-04-29 2009-10-30 Electricite De France Vertical concrete wall's sealing defect detecting device for water pool in nuclear installation, has sensor measuring speed of liquid when sealing device is contacted with wall having sealing defect, to force liquid from end towards chamber
EP2746790A2 (en) 2012-12-24 2014-06-25 Akademia Morska The method and circuit for measuring own and mutual thermal resistances of a magnetic device
EP1653227B1 (en) * 2003-07-11 2017-10-25 SUN-A Corporation Device and method of detecting liquid kind

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2728060A1 (en) * 1977-06-22 1979-01-18 Bosch Gmbh Robert MEASURING PROBE WITH TEMPERATURE DEPENDENT RESISTANCE FOR QUANTITY MEASUREMENT
DE2900220A1 (en) * 1979-01-04 1980-07-17 Bosch Gmbh Robert DEVICE FOR MEASURING THE MASS OF A FLOWING MEDIUM
FR2456950A1 (en) * 1979-05-14 1980-12-12 Sereg Soc Cell for thermal conductivity measurement - operates on voltage change required to maintain constant filament temperature
DE3128882A1 (en) * 1981-07-22 1983-02-10 Degussa Ag, 6000 Frankfurt DEVICE FOR MEASURING THE FLOW RATE OF GASES AND LIQUIDS
DE3814576A1 (en) * 1988-04-29 1989-11-09 Schmidt Feinmech SENSOR

Family Cites Families (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE858777C (en) * 1941-07-13 1952-12-08 Basf Ag Device for gas analysis by measuring the heat conductivity
US2694928A (en) * 1948-07-29 1954-11-23 Mine Safety Appliances Co Electrical system for measuring the rate of motion of a fluid
US2726546A (en) * 1952-03-26 1955-12-13 Jr Robert W King Apparatus for measuring fluid flow

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3130817A1 (en) * 1981-08-04 1983-02-24 Leybold-Heraeus GmbH, 5000 Köln HEATING PIPE VACUUM METER
DE19617238A1 (en) * 1996-04-30 1997-11-06 Leybold Vakuum Gmbh Circuit for temperature compensation of a thermal conduction vacuum meter
EP1653227B1 (en) * 2003-07-11 2017-10-25 SUN-A Corporation Device and method of detecting liquid kind
DE102006027420A1 (en) * 2006-06-13 2007-12-27 Siemens Ag Hot film anemometer for air mass measurement of airflow in internal combustion engine, has sensor units embedded in flow-type body such that side of units directed against direction of air flow is protected from contamination due to airflow
DE102006027420B4 (en) * 2006-06-13 2008-05-08 Siemens Ag Hot-film anemometer with sensor elements embedded in a flow body
FR2930640A1 (en) * 2008-04-29 2009-10-30 Electricite De France Vertical concrete wall's sealing defect detecting device for water pool in nuclear installation, has sensor measuring speed of liquid when sealing device is contacted with wall having sealing defect, to force liquid from end towards chamber
EP2746790A2 (en) 2012-12-24 2014-06-25 Akademia Morska The method and circuit for measuring own and mutual thermal resistances of a magnetic device

Also Published As

Publication number Publication date
DE2710473A1 (en) 1977-09-15

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee