Abstract: A substrate is put in flow of fluid, on which substrate a depression is formed. A film is disposed on an opening plane of the depression. A pair of heating elements, through each of which an electric current flows, are formed on the film at an upstream side and a downstream side of the flow of the fluid. A constant temperature-distribution arrangement is made in which the temperature distribution in each heating element when the electric current flows therethrough is constant along a longitudinal direction perpendicular to a direction in which the fluid flows.

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 surface emission type semiconductor light-emitting device includes a base having a main surface, a current blocking layer formed on the base, and a semiconductor layer formed on the current blocking layer. A circular recess or hole having a side wall which is substantially perpendicular to the main surface is formed in the semiconductor layer as extending therethrough and partly into the base. An impurity is introduced into the semiconductor layer through the side wall and thus there is defined a cylindrical diffusion region around the recess. A p-n junction is defined at an outer boundary of the diffusion region and the p-n junction effectively defines a light-emitting activation region. An additional diffusion region may be formed in the semiconductor layer for narrowing a current path in the semiconductor layer. A second current blocking layer may be formed on top of the semiconductor layer.