GB1174395A - Improvements in or relating to Level Indicators - Google Patents

Improvements in or relating to Level Indicators

Info

Publication number
GB1174395A
GB1174395A GB07970/66A GB1797066A GB1174395A GB 1174395 A GB1174395 A GB 1174395A GB 07970/66 A GB07970/66 A GB 07970/66A GB 1797066 A GB1797066 A GB 1797066A GB 1174395 A GB1174395 A GB 1174395A
Authority
GB
United Kingdom
Prior art keywords
capacitance
output
amplifier
bridge
resistors
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
GB07970/66A
Inventor
John Ernest Fielden
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.)
Fielden Electronics Ltd
Original Assignee
Fielden Electronics 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 Fielden Electronics Ltd filed Critical Fielden Electronics Ltd
Priority to GB07970/66A priority Critical patent/GB1174395A/en
Publication of GB1174395A publication Critical patent/GB1174395A/en
Expired legal-status Critical Current

Links

Classifications

    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/22Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water
    • G01F23/26Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields
    • G01F23/263Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors
    • G01F23/266Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm by measuring physical variables, other than linear dimensions, pressure or weight, dependent on the level to be measured, e.g. by difference of heat transfer of steam or water by measuring variations of capacity or inductance of capacitors or inductors arising from the presence of liquid or fluent solid material in the electric or electromagnetic fields by measuring variations in capacitance of capacitors measuring circuits therefor
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F23/00Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
    • G01F23/80Arrangements for signal processing
    • G01F23/802Particular electronic circuits for digital processing equipment
    • GPHYSICS
    • G01MEASURING; TESTING
    • G01FMEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
    • G01F25/00Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
    • G01F25/20Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume of apparatus for measuring liquid level

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • Fluid Mechanics (AREA)
  • General Physics & Mathematics (AREA)
  • Power Engineering (AREA)
  • Signal Processing (AREA)
  • Electromagnetism (AREA)
  • Thermal Sciences (AREA)
  • Measurement Of Levels Of Liquids Or Fluent Solid Materials (AREA)
  • Indication And Recording Devices For Special Purposes And Tariff Metering Devices (AREA)

Abstract

1,174,395. Electro-physical measurement - fluid level. FIELDEN ELECTRONICS Ltd. April 24, 1967 [April 25, 1966], No. 17970/66. Heading G1N. A capacitance level gauge output is rendered independent of the di-electric constant of the material being measured by having, in addition to the measuring electrode 3, Fig. 1, which extends over the range of levels to be measured, a second electrode 6 which is below the minimum level and therefore always immersed, and arranging converters 7, 8, to produce D.C. signals proportional to the respective capacitance variations and supply them to a self-balancing bridge. The converter 8 produces a direct current dependent upon the variation of capacitance 6 due only to variations in di-electric constant, and energizes the bridge, which consists of two series resistors 26, 27 in parallel with two parallel resistors 28, 29, the resistor 28 being adjustable for calibration, and the resistors 27, 29 having sliding taps 30, 31 between which the bridge output is taken. This output is compared with the D.C. voltage output of converter 7 which depends upon capacitance changes due largely to level changes, but also to di-electric changes. The difference signal drives a motor 33 to rebalance the bridge (at 31) and to operate a pointer 34, the converters 7, 8 once the resistors 27, 28 being adjusted so that di-electric dependent changes in voltage cancel. The converters are basically similar, and each comprises Figs.2, 3 (not shown) a periodically operated switch (13) which connects the appropriate electrodes (3, 6) alternately to a D.C. source (11) and then to a capacitor (12) into which it discharges. The mean voltage on the capacitor (12) is compared with a second D.C. source (15) and after smoothing (16, 17, 19) passes to an amplifier (18). A feedback resistor (21) is connected to one input of the amplifier from the output of the amplifier (Fig. 2) where a capacitance dependent voltage E out is required, and from a potential dropping resistor (25, Fig. 3) in the return path of the amplifier output, where a capacitance dependent current I out is required.
GB07970/66A 1966-04-25 1966-04-25 Improvements in or relating to Level Indicators Expired GB1174395A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB07970/66A GB1174395A (en) 1966-04-25 1966-04-25 Improvements in or relating to Level Indicators

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB07970/66A GB1174395A (en) 1966-04-25 1966-04-25 Improvements in or relating to Level Indicators

Publications (1)

Publication Number Publication Date
GB1174395A true GB1174395A (en) 1969-12-17

Family

ID=10104380

Family Applications (1)

Application Number Title Priority Date Filing Date
GB07970/66A Expired GB1174395A (en) 1966-04-25 1966-04-25 Improvements in or relating to Level Indicators

Country Status (1)

Country Link
GB (1) GB1174395A (en)

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4202267A (en) * 1976-04-23 1980-05-13 Siemens Aktiengesellschaft Device for monitoring the ink supply in ink-operated printers
US4782754A (en) * 1986-03-07 1988-11-08 Siemens Aktiengesellschaft Mechanism having ink reservoir with electrodes for ink monitoring in ink printer devices
WO2004083791A1 (en) * 2003-03-21 2004-09-30 Saab Rosemount Tank Radar Ab System and method in a radar level gauging system
CN100356145C (en) * 2003-03-21 2007-12-19 罗斯蒙特雷达液位股份公司 System and method in a radar level gauging system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4202267A (en) * 1976-04-23 1980-05-13 Siemens Aktiengesellschaft Device for monitoring the ink supply in ink-operated printers
US4782754A (en) * 1986-03-07 1988-11-08 Siemens Aktiengesellschaft Mechanism having ink reservoir with electrodes for ink monitoring in ink printer devices
WO2004083791A1 (en) * 2003-03-21 2004-09-30 Saab Rosemount Tank Radar Ab System and method in a radar level gauging system
CN100356145C (en) * 2003-03-21 2007-12-19 罗斯蒙特雷达液位股份公司 System and method in a radar level gauging system

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Legal Events

Date Code Title Description
PS Patent sealed [section 19, patents act 1949]
PLE Entries relating assignments, transmissions, licences in the register of patents
PLNP Patent lapsed through nonpayment of renewal fees