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US 4,283,944 AGranted
Apparatus for measuring the mass of a fluid medium
AssigneeRobert Bosch GmbH
InventorsHeiko Gruner, Dieter Handtmann
Life of this patent
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AssigneeRobert Bosch GmbH
InventorsHeiko Gruner, Dieter Handtmann
Estimating the term…
An apparatus is proposed for measuring the mass of a fluid medium such as the mass of air induced by internal combustion engines which has at least one temperature-dependent measuring resistor film disposed in the flow of the medium, whose temperature and/or resistance is regulated in accordance with the mass of the medium and wherein the manipulated variable is a measure for the mass of the medium. The temperature-dependent measuring resistor film is disposed on a carrier separated therefrom by an insulating film and a temperature-dependent heating resistor film. The temperature of the heating resistor film is regulated to approximately the same temperature as the temperature-dependent measuring resistor film so that a heat flow between the temperature-dependent measuring resistor and the carrier is prevented. As a result, the response speed of the apparatus to changes in the flow rate of the medium is substantially improved as is the precision of measurement.
An apparatus for measuring the mass of a fluid medium such as the mass of air induced in internal combustion engines comprising, in combination, a measuring bridge circuit, a carrier, at least one temperature-dependent measuring resistor connected in said measuring bridge circuit and disposed in the flow of said medium, said at least one temperature-dependent measuring resistor applied as a film to said carrier, the temperature and/or resistance of said resister being regulated in accordance with the flowing mass to provide a manipulated variable as a measure for the mass of the fluid medium, a temperature-dependent heating resistor applied as a film to said carrier between the temperature-dependent measuring resistor and the carrier in electrically insulated relationship with said temperature-dependent measuring resistor, a heating bridge circuit including said temperature-dependent heating resistor wherein said temperature-dependent heating resistor is regulated to approximately the same temperature as said temperature-dependent measuring resistor.
Dependencies are inferred from the claim text.