Fluid flow sensor and fluid flow measurement device
AssigneesHitachi, Ltd., Hitachi Car Engineering Co., Ltd.
InventorsKeiichi Nakada, Junichi Horie, Hiroshi Nakano, Izumi Watanabe
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Abstract
A Thermal type fluid flow sensor comprises a heating resistor formed on a thin film of a substrate, and plural thermal sensitive resistors configuring a bridge circuit. The thermal sensitive resistors are disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured. Resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.
Claims20
A Thermal type fluid flow sensor comprising:
- a heating resistor formed on a thin film of a substrate, and
- plural thermal sensitive resistors configuring a bridge circuit and being disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured, wherein
- resistor traces for the thermal sensitive resistors are formed so that the respective thermal sensitive resistors exhibit substantially equal changes in resistance with each other to distortion caused in the thin film.
A Thermal type fluid flow sensor comprising:
- a heating resistor formed on a thin film of a substrate, and
- plural thermal sensitive resistors configuring a bridge circuit and being disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured, wherein
- resistor traces for the thermal sensitive resistors are formed so that the sum for the length of trace-portions in one direction is substantially equal with the sum for the length of trace-portions in another direction perpendicular to said one direction, and these resistor traces have a substantially identical width.
A Thermal type fluid flow sensor comprising:
- a heating resistor formed on a thin film of a substrate, and
- plural thermal sensitive resistors configuring a bridge circuit and being disposed on the thin film of the substrate so as to be located on an adjacent upstream side and an adjacent downstream side of the heating resistor in a stream direction of fluid to be measured, wherein
- the thermal sensitive resistors disposed symmetrically relative to the heating resistor are connected electrically to be formed as the bridge circuit.
Dependencies are inferred from the claim text.