GB616272A - Improvements in or relating to electrically operated indicating devices - Google Patents
Improvements in or relating to electrically operated indicating devicesInfo
- Publication number
- GB616272A GB616272A GB28525/45A GB2852545A GB616272A GB 616272 A GB616272 A GB 616272A GB 28525/45 A GB28525/45 A GB 28525/45A GB 2852545 A GB2852545 A GB 2852545A GB 616272 A GB616272 A GB 616272A
- Authority
- GB
- United Kingdom
- Prior art keywords
- liquid
- condenser
- condensers
- capacitance
- indicator
- 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
Links
Classifications
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F23/00—Indicating or measuring liquid level or level of fluent solid material, e.g. indicating in terms of volume or indicating by means of an alarm
- G01F23/22—Indicating 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
- G01F23/26—Indicating 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
- G01F23/263—Indicating 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
Landscapes
- Physics & Mathematics (AREA)
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Electromagnetism (AREA)
- Thermal Sciences (AREA)
- Fluid Mechanics (AREA)
- General Physics & Mathematics (AREA)
- Level Indicators Using A Float (AREA)
Abstract
616,272. Indicating liquid-levels. LIQUIDOMETER CORPORATION. Oct. 29, 1945, No. 28525. Convention date, Feb. 1. [Class 37] A liquid-level gauge or other displacement indicator is controlled by two or more circuits each responsive to capacitative changes. At least one of the capacitors in each circuit is variable in accordance with the displacement to be measured and means are provided for compensating relative changes of the capacitance of the two or more capacitors caused by a change of the dielectric constant of an identical component of each-capacitor so that the indication is independent of variations in this dielectric constant. The invention is particularly applicable to liquid level gauges where the liquid forms part of the dielectric of a condenser and compensates for changes in the dielectric constant of the liquid. As shown, the liquid level in one tank or the amount of liquid in one or more tanks 15, Fig. 1, varies the capacitance 5<1> correspondingly. The capacitance 5<1> and a similar capacitance 5, i.e. one formed by plates immersed to a constant depth in the same liquid are connected in respective bridge circuits fed from a source 1, the bridge outputs being fed through rectifiers 8, 8<1> and smoothing condensers 10, 10<1> to the respective coils 9, 9<1> of a resultant field indicator 12 having a permanent magnet rotor 11. The bridges are both balanced when capacitors 5, 5<1> have air as dielectric. Liquid is then admitted to fill condenser 5, whereupon the coil 9 is energized to move the pointer 12 to the empty position. Admission of liquid to the measuring condensers 5<1> then energizes coil 91 to move the indicator correspondingly. Any change in dielectric constant of the liquid will affect both bridges and therefore both coils 9, 9<1> so that the indicator reading is independent of such changes. In a modification, Fig. 2, the condensers 5, 5<1> are fed in parallel from source 1 through respective rectifiers 8, 8<1>. Initially, with air forming the dielectric of both condensers, the currents therethrough are balanced against the currents in inductors 41, 41<1> in parallel therewith, so that both meter coils 9, 9<1> are de-energized. Liquid is then admitted as before, first to the condenser 5 to establish the " empty " position and then to 5<1>. In another modification, Fig. 3, three condensers 51<1>, 51<11>, 51<111> are connected in the oscillatory circuits of respective oscillators 1<1>, 1<11>, 1<111>. The three condensers are combined in a single assembly, Fig. 4 (not shown), their capacitances varying differently as the liquid level rises. As the oscillators are locked to the same frequency these capacitance variations cause corresponding phase-shifts at the points 6<1>, 6<11>, 6<111>, whereby the coils 91, 9<11>, 9<111> of the resultant field indicator are energized and produce a reading corresponding to the liquid level. The condenser plates are shaped to produce the desired deflection law of the indicator and one of them may be extended below the others to produce a zeroizing current in the meter coils. If, however, the coil currents are all zero at "empty," a zeroizing permanent magnet 102 may be provided. The pointer may be arranged to deflect several revolutions. Condenser constructions are described. The condenser 5, Fig. 1, may be fitted in the same tank and so arranged that as the liquid therein rises the air above it is forced out through a valve, whereby the condenser 5 may be maintained full even although the liquid level of the tank may fall. The invention is applicable to electrically-conducting liquids in which case some of the condenser electrodes must be insulated, and to powdered materials or semi-liquids. The invention is also applicable to capacitance arrangements which indicate the approach of a body into an electric field.
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US616272XA | 1945-02-01 | 1945-02-01 |
Publications (1)
Publication Number | Publication Date |
---|---|
GB616272A true GB616272A (en) | 1949-01-19 |
Family
ID=22037032
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
GB28525/45A Expired GB616272A (en) | 1945-02-01 | 1945-10-29 | Improvements in or relating to electrically operated indicating devices |
Country Status (1)
Country | Link |
---|---|
GB (1) | GB616272A (en) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2230100A (en) * | 1989-03-06 | 1990-10-10 | Raytheon Co | Fluid level sensor and controller |
-
1945
- 1945-10-29 GB GB28525/45A patent/GB616272A/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB2230100A (en) * | 1989-03-06 | 1990-10-10 | Raytheon Co | Fluid level sensor and controller |
US4982606A (en) * | 1989-03-06 | 1991-01-08 | Raytheon Company | Fluid level sensor and controller |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US2581085A (en) | Liquid level gauge | |
US3932810A (en) | Temperature compensated combined current and voltage measuring apparatus | |
US2409073A (en) | Capacitor fuel gauge | |
US4373389A (en) | Device for capacitive level measurement | |
US2300562A (en) | Fuel container sounding device | |
US2280678A (en) | Apparatus for the measurement of electrical reactance | |
US2622442A (en) | Apparatus for measuring liquid levels | |
US2724273A (en) | Liquid weight gauging apparatus | |
US2866336A (en) | Liquid level gage | |
US2371395A (en) | Electrical instrument | |
US2657579A (en) | Liquid level indicating device | |
US2769338A (en) | Fuel gage apparatus | |
US2741124A (en) | Fuel quantity measuring apparatus | |
US2638000A (en) | Bridge-type capacitance liquid level gauge | |
US4069710A (en) | Apparatus for the capacitative measurement of the surface level of fluid media in vessels | |
GB616272A (en) | Improvements in or relating to electrically operated indicating devices | |
US3793585A (en) | Moisture monitor having a resistor between sensing capacitor and oscillator tuned input to improve oscillator response | |
US3221247A (en) | Solid state capacity servo measuring system utilizing inductive feedback | |
US2789435A (en) | Capacitive liquid measuring apparatus | |
US2710541A (en) | Apparatus for volume measurement | |
US3037385A (en) | Fluid quantity measuring apparatus | |
US3112647A (en) | Measuring system with compensation for dielectric constant | |
US2688875A (en) | Airplane fuel gauge | |
USRE23493E (en) | Liquid level uaige | |
US2793529A (en) | Fluid quantity measuring apparatus |