Abstract: A thin-film microstructure sensor includes a substrate having an insulation layer. A thin-film platinum temperature-sensitive resistor is provided on the insulation layer of the substrate, the thin-film platinum temperature-sensitive resistor comprising a platinum layer, the platinum layer having a maximum crystal grain size above a reference grain size of 800 Å. The thin-film platinum temperature-sensitive resistor is formed by a sputtering process to provide a temperature coefficient of resistance TCR above a reference TCR level of 3200 ppm.

Abstract: A thin-film microstructure sensor includes a substrate having an insulation layer. A thin-film platinum temperature-sensitive resistor is provided on the insulation layer of the substrate, the thin-film platinum temperature-sensitive resistor comprising a platinum layer, the platinum layer having a maximum crystal grain size above a reference grain size of 800 .ANG.. The thin-film platinum temperature-sensitive resistor is formed by a sputtering process to provide a temperature coefficient of resistance TCR above a reference TCR level of 3200 ppm.

Abstract: A method of calibrating a zero point of a flow sensor includes the steps of detecting a transition of output of the flow sensor caused in response to a shut down of a fluid, and adjusting the zero point of a characteristic curve representing the output of the flow sensor and a flow rate, such that the indicated flow rate is zero immediately after the transition of the flow sensor output.

Abstract: A flow sensor includes a first heating portion, provided at a first position in a flow of a fluid, which heats the fluid and outputs a voltage in response to a temperature of the first position. A second heating portion, provided at a second, downstream position in the flow of the fluid, heats the fluid and outputs a voltage in response to a temperature of the second position, the first position and the second position being spaced from each other in a direction parallel to the flow of the fluid. An intermediate heater, provided between the first heating portion and the second heating portion, heats the fluid at an intermediate position between the first position and the second position.

Abstract: A flow sensor eliminates turbulence of fluid flow due to a structure of the temperature detecting portion so that a temperature of the temperature detecting portions does not fluctuate due to the turbulence of the fluid. The flow sensor is formed on a substrate. Each of a first temperature detecting portion and a second temperature detecting portion has a heating function and a temperature detecting function, and are arranged along a direction of flow of the fluid. A supporting portion is formed on the substrate for supporting the first and second temperature detecting portions thereon. The supporting portion does not have a side surface facing substantially in the direction of flow of the fluid. A side surface of the supporting portion is protected by a guard portion formed along the side surface.