FR1451423A - Improvements in mass flow measurement devices - Google Patents

Improvements in mass flow measurement devices

Info

Publication number
FR1451423A
FR1451423A FR24886A FR75024886A FR1451423A FR 1451423 A FR1451423 A FR 1451423A FR 24886 A FR24886 A FR 24886A FR 75024886 A FR75024886 A FR 75024886A FR 1451423 A FR1451423 A FR 1451423A
Authority
FR
France
Prior art keywords
gas
flow
thermistor
bridge
heater
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
FR24886A
Other languages
French (fr)
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.)
Hawker Siddeley Dynamics Ltd
Original Assignee
Hawker Siddeley Dynamics 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 Hawker Siddeley Dynamics Ltd filed Critical Hawker Siddeley Dynamics Ltd
Application granted granted Critical
Publication of FR1451423A publication Critical patent/FR1451423A/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

Landscapes

  • Physics & Mathematics (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Measuring Volume Flow (AREA)

Abstract

1,109,118. Measuring gas-flow electrically. HAWKER SIDDELEY DYNAMICS Ltd. July 13, 1965 [July 19, 1964], No.9645/64. Heading G1N. Apparatus for measuring the mass flow of a gas comprises a thermistor 2a (Fig. 1) in one arm of a bridge 1, electrically heated by an element 4 exposed to the gas-flow, the heater being fed with the bridge unbalance current, whereby an increase in the gas-flow reduces the temperature of thermistor 2a and unbalances the bridge, thereby feeding more current to the heater 4 to restore the bridge balance condition, the change in heater current, indicated at 7, representing the change in gas mass flow. As shown, five thermistors 2, 2a, 3 are connected in the bridge circuit and located in the gas-stream so that the bridge is insensitive to changes in the temperature of the gas. Thermistors 2 and 3 are thermally shielded from thermistor 2a and the heater 4. Thermistor 3 is connected in one arm in series with 2a to determine the heater current at zero gas-flow. In a modification, thermistor 3 is omitted and an A. C . voltage is added in the unbalance circuit to determine the initial heater current Fig. 6 (not shown). Thermistors 2 may be combined with or replaced by fixed resistors to produce the desired relationship between heater current and gas mass flow. The thermistors may be located in the main flow conduit or in a by-pass. In one embodiment Fig. 10 (not shown) a further thermistor in the gas-flow is used to control the gains of the unbalance amplifier to make the response independent of changes in the gas temperature.
FR24886A 1964-07-19 1965-07-16 Improvements in mass flow measurement devices Expired FR1451423A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB964564A GB1109118A (en) 1964-07-19 1964-07-19 Improvements in or relating to mass flow measuring devices

Publications (1)

Publication Number Publication Date
FR1451423A true FR1451423A (en) 1966-01-07

Family

ID=9876002

Family Applications (1)

Application Number Title Priority Date Filing Date
FR24886A Expired FR1451423A (en) 1964-07-19 1965-07-16 Improvements in mass flow measurement devices

Country Status (3)

Country Link
DE (1) DE1498351A1 (en)
FR (1) FR1451423A (en)
GB (1) GB1109118A (en)

Families Citing this family (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE1905999A1 (en) * 1969-02-07 1970-09-03 Interatom Method and device for measuring the flow rate of gases and liquids
US3735752A (en) * 1971-04-07 1973-05-29 J Rodder Spirometer
SE391036B (en) * 1973-12-03 1977-01-31 Elektronik Konstruktions Ab DEVICE FOR SATURATION AND / OR MONITORING THE FLOW SPEED OF A FLOWING MEDIUM
FR2439388A1 (en) * 1978-10-20 1980-05-16 Bosch Gmbh Robert INSTALLATION FOR MEASURING THE MASS OF A FLOWING FLUID
DE2849467C2 (en) * 1978-11-15 1982-12-30 Robert Bosch Gmbh, 7000 Stuttgart Control circuit for a constant temperature anemometer, especially for measuring the intake air of an internal combustion engine

Also Published As

Publication number Publication date
DE1498351A1 (en) 1968-12-05
GB1109118A (en) 1968-04-10

Similar Documents

Publication Publication Date Title
US2501377A (en) Relative humidity measuring system
GB1214266A (en) A method and apparatus for measurement by determining the temperature of a thermosensitive element heated by the joule effect
GB1252304A (en)
FR1451423A (en) Improvements in mass flow measurement devices
US3048778A (en) High frequency power meter
GB806442A (en) Improvements in and relating to the measurement of the rate of flow of fluids
GB1291827A (en) Improvements in or relating to temperature measuring apparatus
GB1143002A (en) Improvements in or relating to wheatstone bridge circuit arrangements
US2674719A (en) Temperature-compensating measuring system
GB835551A (en) Improvements in and relating to temperature measuring devices
GB1129128A (en) Apparatus for measuring the concentration of combustible gases and vapours
GB1073189A (en) Improvements in and relating to electrical measuring and like instruments
US1482091A (en) Apparatus for determining and also indicating the total available heat of a flow of combustible fluid
GB840159A (en) Combustible gas testing apparatus
SU542511A1 (en) Device for measuring the temperature of inhaled and exhaled air
GB991006A (en) Improvements in or relating to the measurement of heat
SU821952A2 (en) Temperature measuring device
GB931749A (en) Improvements in control devices
SU365654A1 (en) AUTOMATIC DEVICE FOR WORKING WITH SENSORS
GB865142A (en) Transmitter potentiometer
GB761880A (en) Improvements in and relating to a device for recording the density of a liquid
GB969061A (en) Improvements in or relating to the measurement of heat
GB791882A (en) Improved temperature control device
GB966042A (en) Improvements in or relating to methods for thermistor matching
GB1489874A (en) Apparatus and methods of measuring fluid flow