US3648518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for measuring the flow volume of gases and liquids
Assignee: Individual
•
Filing: 1970-02-05
•
Granted: 1972-03-14
•
Expires: 1990-02-05
Abstract
Abstract An apparatus for measuring the flow volume of gases and liquids by measuring the difference, between the voltage drop of an ohmic resistance, heated to measuring temperature and encompassed by the medium to be measured, and a second comparison resistance encompassed by the medium and constituting the reference value by a bridge network. Because of the medium-produced cooling of the measuring body formed by the resistance coil, the unbalance of the bridge network controls the replenishment of the heating power to be supplied by the measuring body, for producing the balance of the bridge network. The replenished heating power represents, in accordance with the resistance change of the measuring coil, the rate for the flow through volume.
Inventors
- 👤 Rainer Hans
- 👤 Michael Lancier
- 👤 Hermann Becher
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-03 05:19
CPC Classifications
G; G01; G01F; G01F1/00; G01F1/68; G01F1/684; G01F1/696; G01F1/698
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
237 words
Apparatus for measuring the flow volume of liquid and gases which comprises a tubular measuring body axially arranged in a conduit traversed by the fluid to be measured, said measuring body comprising a heating wire helically wound into a cylindrical shape and forming a center coil, and two further wires also helically wound into cylindrical shape and forming measuring coils placed in close thermal contact with said central heating coil by being arranged coaxially with it, one measuring coil being placed within said heating coil and the other without said heating coil, mechanical contact between the coils being established in both cases, a reference coil situated upstream of the measuring body, an electrical bridge circuit having as one arm the said reference coil, both measuring coils as another arm and one fixed resistance as each of the remaining arms, a constant source of electric energy and first, second and third amplifiers, the first amplifier connected to the bridge output and the second amplifier, the second amplifier output connected to the heating coil thereby increasing the voltage to the heating coils until the measuring coils, being heated by the heating coil, attain a temperature sufficient to rebalance the bridge, the voltage from the constant energy source connected to the two fixed resistors, the voltage supplied to the heating coil amplified by the third amplifier, being proportional to the amount of fluid traversing the conduit at the given moment.
Claim 2
Dependent Claim
237 words
Apparatus for measuring the flow volume of liquid and gases which comprises a tubular measuring body axially arranged in a conduit traversed by the fluid to be measured, said measuring body comprising a heating wire helically wound into a cylindrical shape and forming a center coil, and two further wires also helically wound into cylindrical shape and forming measuring coils placed in close thermal contact with said central heating coil by being arranged coaxially with it, one measuring coil being placed within said heating coil and the other without said heating coil, mechanical contact between the coils being established in both cases, a reference coil situated upstream of the measuring body, an electrical bridge circuit having as one arm the said reference coil, both measuring coils as another arm and one fixed resistance as each of the remaining arms, a constant source of electric energy and first, second and third amplifiers, the first amplifier connected to the bridge output and the second amplifier, the second amplifier output connected to the heating coil thereby increasing the voltage to the heating coils until the measuring coils, being heated by the heating coil, attain a temperature sufficient to rebalance the bridge, the voltage from the constant energy source connected to the two fixed resistors, the voltage supplied to the heating coil amplified by the third amplifier, being proportional to the amount of fluid traversing the conduit at the given moment.
Claim 3
Dependent Claim
58 words
The apparatus of claim 1, wherein the measuring body is arranged centrically in a pipe section expanded in its inner diameter and passed by the medium to be measured and that the reference coil winding is arranged in flow direction ahead of the measuring body and also positioned in the region of the wall of the supply tube.
Claim 4
Dependent Claim
29 words
The apparatus of claim 2, wherein the reference coil winding is placed outside on the wall of the pipe section which is connected in series with the expanded diameter.
Claim 5
Dependent Claim
28 words
The apparatus of claim 2, wherein the reference coil winding within the passed tubular section ahead of the expanded diameter is wetted by the medium to be measured.
Claim 6
Dependent Claim
40 words
The apparatus of claim 1, wherein a compensation heating coil winding is embedded in the wall of the measuring section of expanded diameter in order to compensate for the outer pressure and temperature fluctuations which occur during the measuring process.
References Cited (Backward Citations)
US2412471A
Cited
US2953022A
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US3085431A
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US3246515A
Cited
GB1109118A
Cited
US3425277A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-03-14 | 1975-09-13 | 1976-03-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-03-14 | 1979-09-13 | 1980-03-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-03-14 | 1983-09-13 | 1984-03-14 | $7700.00 | Window Closed / Lapsed |