GB1174395A - Improvements in or relating to Level Indicators - Google Patents
Improvements in or relating to Level IndicatorsInfo
- 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
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
- G01F23/266—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 measuring circuits therefor
-
- 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
- G01F23/80—Arrangements for signal processing
- G01F23/802—Particular electronic circuits for digital processing equipment
-
- G—PHYSICS
- G01—MEASURING; TESTING
- G01F—MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUID LEVEL; METERING BY VOLUME
- G01F25/00—Testing or calibration of apparatus for measuring volume, volume flow or liquid level or for metering by volume
- G01F25/20—Testing 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.
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)
| 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 |
-
1966
- 1966-04-25 GB GB07970/66A patent/GB1174395A/en not_active Expired
Cited By (4)
| 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 |