초록 ▼

The invention relates to a connection piece (20), comprising an upper connection piece part (21) and a connection piece wall (22) disposed below said upper connection piece part (21) and having a connection piece wall height (h). In said upper connection piece part (21), a level metering device (10)

The invention relates to a connection piece (20), comprising an upper connection piece part (21) and a connection piece wall (22) disposed below said upper connection piece part (21) and having a connection piece wall height (h). In said upper connection piece part (21), a level metering device (10) working on the guided microwave principle and comprising a single electric line (40) can be mounted. Connection piece (20) further comprises at least one electrical conductor (30a, 30b, 30c, 30d, 30e, 30f) spaced apart at a distance (a, a') from the single electric line (40) of the level metering device (10) to be mounted on the upper connection piece part (21) and extending from the upper connection piece part (21) up to at least the 0.25-fold, and maximally up to the 2.5-fold of the connection piece wall height (h). By arranging at least one electrical conductor (30a, 30b, 30c, 30d, 30e, 30f) in said connection piece (20), previous interfering influences caused by connection piece (20) during a filling level measurement are reduced. The invention further relates to a combination of a level metering device comprising a single-wire line, an attachment means and at least one additional electrical conductor having a limited length.

대표청구항 ▼

The invention relates to a connection piece (20), comprising an upper connection piece part (21) and a connection piece wall (22) disposed below said upper connection piece part (21) and having a connection piece wall height (h). In said upper connection piece part (21), a level metering device (10)

The invention relates to a connection piece (20), comprising an upper connection piece part (21) and a connection piece wall (22) disposed below said upper connection piece part (21) and having a connection piece wall height (h). In said upper connection piece part (21), a level metering device (10) working on the guided microwave principle and comprising a single electric line (40) can be mounted. Connection piece (20) further comprises at least one electrical conductor (30a, 30b, 30c, 30d, 30e, 30f) spaced apart at a distance (a, a') from the single electric line (40) of the level metering device (10) to be mounted on the upper connection piece part (21) and extending from the upper connection piece part (21) up to at least the 0.25-fold, and maximally up to the 2.5-fold of the connection piece wall height (h). By arranging at least one electrical conductor (30a, 30b, 30c, 30d, 30e, 30f) in said connection piece (20), previous interfering influences caused by connection piece (20) during a filling level measurement are reduced. The invention further relates to a combination of a level metering device comprising a single-wire line, an attachment means and at least one additional electrical conductor having a limited length. aid fluid at a first location along said path; a first electrically responsive temperature sensor located downstream from said heating means for said first direction of fluid flow, said first temperature sensor having a first temperature-dependent constant-electrical-current characteristic; a second electrically responsive temperature sensor located downstream from said heating means for said second direction of fluid flow, said second temperature sensor having a second temperature-dependent constant-electrical-current characteristic; sensor coupling means electrically coupled to said first and second electrically responsive temperature sensors, for coupling said sensors in electrical series in a manner which results in a electrical combined sensor current which depends only on that one of said sensors providing the lesser constant electrical current; control means coupled to said sensor coupling means and to said heating means, for controlling the power applied to said heating means in a manner which tends to maintain said heating means at a fixed temperature difference above the temperature of that one of said sensors providing the lesser constant electrical current; and processing means for converting a signal representing said power applied into an indication of flow. 6. A flow sensor according to claim 5, wherein said constant-electrical-current characteristic of said first and second electrically responsive temperature sensors has a constant current which increases with temperature, whereby said electrical combined sensor current represents the temperature of that one of said first and second temperature sensors which is at the lower temperature. 7. A flow sensor according to claim 5, wherein said control means comprises a heater temperature determining means coupled to said heating means, for determining the temperature of said heating means. 8. A flow sensor according to claim 7, wherein said heater temperature determining means comprises an electrical resistor associated with said heating means, and means for determining the electrical resistance of said electrical resistor. 9. A flow sensor according to claim 7, wherein said heating means comprises an electrical resistor, and said heater temperature determining means further comprises means coupled to said electrical resistor for measuring the electrical resistance of said heating means. 10. A flow sensor according to claim 5, wherein said control means comprises a memory preprogrammed with a value corresponding to the cross-sectional area of said path, and said flow determination is in the form of one of mass quantity per unit time and volume per unit time. 11. A flow sensor according to claim 5, wherein said path is associated with a pipe having a peripheral wall, and wherein said heating means is in the form of a peripheral structure surrounding said peripheral wall, and in thermal contact therewith. 12. A flow sensor according to claim 11, wherein said peripheral wall of said pipe is made from conventional materials having a thickness commensurate with the pressure and temperature of said fluid, except in the region in which said heating means is thermally coupled, in which region said peripheral wall is made from a material having higher strength than said conventional materials, of a thickness less than said commensurate thickness. 13. A sensor according to claim 5, further comprising processing means coupled to said first and second electrically responsive temperature sensors, for comparing the voltages at said sensors, and for generating a flow direction signal representative of the direction of fluid flow in said path. 14. A method for determining the flow of a fluid through a region, said method comprising the steps of: determining the temperature of a fluid flowing in a path, at first and second spaced-apart locations along said path; applying power to a heater thermally coupled to said path at a location lying between said first and second spac ed-apart locations, for raising the temperature of said heater by a fixed temperature differential above the lesser of the temperature of the fluid at said first and second locations; and from a signal representing said power applied to said heater, determining the quantitative value of one of volumetric and mass fluid flow. 15. A method according to claim 14, further comprising the step of comparing signals related to said temperature of said fluid at said first and second spaced-apart locations, for determining the direction of fluid flow in said path. 16. A method according to claim 14, further comprising the step of determining the volumetric flow from said fluid flow and information equivalent to the cross-sectional area of said path. 17. A method according to claim 16, further comprising the step of determining the:mass flow from said volumetric flow and information equivalent to the mass density of said fluid. 18. A bidirectional fluid flow sensor, said sensor comprising: a path for the flow of fluid in mutually opposite first and second directions; a heater thermally coupled to said path, for transferring heat to said fluid at a first location along said path; a first electrically responsive temperature sensor located downstream from said heater for said first direction of fluid flow, said first temperature-sensor having a temperature-dependent constant-electrical-current characteristic; a second electrically responsive temperature sensor located downstream from said heater for said second direction of fluid flow, said second temperature sensor having a temperature-dependent constant-electrical-current characteristic which may differ from that of said first electrically responsive temperature sensor; an electrical coupler electrically coupled to said first and second electrically responsive temperature sensors, for coupling said sensors in electrical series in a manner which results in a electrical combined sensor current which depends only on that one of said sensors providing the lesser constant electrical current; a controller coupled to said electrical coupler and to said heater, for controlling the power applied to said heater in a manner which tends to maintain said heater at a fixed temperature difference above the temperature of that one of said sensors providing the lesser constant electrical current; and a processor for converting said power applied into an indication of flow. 19. A flow sensor according to claim 18, further comprising processing means coupled to said first and second electrically responsive temperature sensors, for generating a signal representative of the direction of fluid flow in said path. 20. A flow sensor according to claim 18, wherein said constant-electrical-current characteristic of said first and second electrically responsive temperature sensors has a constant current which increases with temperature, whereby said electrical combined sensor current represents the temperature of that one of said first and second temperature sensors which is at the lower temperature. 21. A flow sensor according to claim 18, wherein said controller comprises a heater temperature sensor coupled to said heater, for determining the temperature of said heater. 22. A flow sensor according to claim 20, wherein said heater temperature sensor comprises an electrical resistor associated with said heater, and a processing arrangement for determining the electrical resistance of said electrical resistor. 23. A flow sensor according to claim 21, wherein said heater comprises an electrical resistor, and said heater temperature sensor further comprises a resistance determining arrangement coupled to said electrical resistor for measuring the electrical resistance of said heater. 24. A flow sensor according to claim 18, wherein said controller comprises a memory preprogrammed with a value corresponding to the cross-sectional area of said path, and said flow determination is in the form of one of mass quantity per unit time and volume per unit time. 25. A flow sensor according to claim 18, wherein said path is associated with a pipe having a peripheral wall, and wherein said heater is in the form of a peripheral structure surrounding said peripheral wall, and in thermal contact therewith. 26. A flow sensor according to claim 25, wherein said peripheral wall of said pipe is made from conventional materials having a thickness commensurate with the pressure and temperature of said fluid, except in the region in which said heater is thermally coupled, in which region said peripheral wall is made from a material having higher strength than said conventional materials, of a thickness less than said commensurate thickness.