A flow velocity sensor includes a substrate, a resistor, and a signal processing section. The substrate has first and second substrate surfaces outwardly opposite to each other. The first substrate surface is exposed to a fluid. The resistor is mounted on the second substrate surface. The resistor has a heat generating portion facing the second substrate surface. The signal processing section is configured to receive a signal from the resister. The signal from the resistor represents heat dissipation of the resistor. A fluid velocity is detected based on the signal from the resistor.

A flow velocity sensor includes a substrate, a resistor, and a signal processing section. The substrate has first and second substrate surfaces outwardly opposite to each other. The first substrate surface is exposed to a fluid. The resistor is mounted on the second substrate surface. The resistor has a heat generating portion facing the second substrate surface. The signal processing section is configured to receive a signal from the resister. The signal from the resistor represents heat dissipation of the resistor. A fluid velocity is detected based on the signal from the resistor.

According to aspects of the embodiments, there is provided a method of measuring the amount of fountain solution using a hot wire anemometer. Fountain solution thickness is measured using the flow rate of vaporized fountain solution and comparing to baseline air only flow rate. The vaporized measurement is correlated with the baseline utilizing specific heat, density and enthalpy values and keeping velocity of fluid constant. Changes in the measurement will then be related to the specific heat, density and enthalpy. Density can be back calculated to yield volume and knowing the area of the image being printed give a real time thickness value.

A method for determining flow properties of a fluid flowing along a surface by: modulating the current through a heating element of a thermal flow sensor located on the surface with at least one modulation frequency, thereby emitting a thermal wave into the fluid flowing along the surface having a penetration depth inversely proportional to the modulation frequency; measuring an amplitude of a voltage across the heating element at the third harmonic of the at least one modulation frequency, the voltage depending on the thermal conductivity and the volumetric heat capacity of the fluid flowing along the surface; determining a flow velocity at the penetration depth from the attenuation value of the determined amplitude of the voltage; and estimating whether the flow at the penetration depth is laminar or turbulent on the basis of the determined flow velocity. Also, a system and an aircraft with such a system.

A method for determining flow properties of a fluid flowing along a surface by: modulating the current through a heating element of a thermal flow sensor located on the surface with at least one modulation frequency, thereby emitting a thermal wave into the fluid flowing along the surface having a penetration depth inversely proportional to the modulation frequency; measuring an amplitude of a voltage across the heating element at the third harmonic of the at least one modulation frequency, the voltage depending on the thermal conductivity and the volumetric heat capacity of the fluid flowing along the surface; determining a flow velocity at the penetration depth from the attenuation value of the determined amplitude of the voltage; and estimating whether the flow at the penetration depth is laminar or turbulent on the basis of the determined flow velocity. Also, a system and an aircraft with such a system.

A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including gels.

A sensor includes a heater, a thermal insulator between two thermometer layers, the heater generating a thermal gradient within the thermal insulator. The thermometers give an indirect measurement of fluid flow around the sensor, based on their temperature readings. The thermometers are flexible layers including gels.

A system and method for measuring multiple velocity components with a single wire, by alternating current through the wire at a sufficiently high frequency, where the first current allows measurement of a first velocity component, and the second current allows measurement of a second velocity component. The resolution of the measurements can be adjusted by altering the frequency at which the current is alternated.

A system and method for measuring multiple velocity components with a single wire, by alternating current through the wire at a sufficiently high frequency, where the first current allows measurement of a first velocity component, and the second current allows measurement of a second velocity component. The resolution of the measurements can be adjusted by altering the frequency at which the current is alternated.

The visibility of light is improved. A flow rate sensor device includes a substrate, sensor elements electrically connected to the substrate, light emitting elements positioned in a rear part of the sensor elements and disposed on a surface of the substrate, and light-transmissive cases internally accommodating the light emitting elements between the light-transmissive cases and the substrate. The light-transmissive cases have light diffusion members projecting from ceiling sections toward the light emitting elements, the light diffusion members have light incident surfaces facing the light emitting elements and wall surfaces connecting the light incident surfaces and the ceiling sections, and at least a part of the wall surfaces has a tilting surface having a dimension between the opposing wall surfaces, the dimension gradually increasing from a side close to the light incident surface toward the ceiling section.