Abstract: An apparatus for measuring the flow of fluid comprising a tube through which the fluid to be measured may flow, including means for varying the temperature at a selected location on the tube. A plurality of temperature sensors are used to measure the temperature at locations on the in flow end, that is upstream of the means for varying the temperature, and at least one sensor is used for measuring the temperature downstream of the selected location. A plurality of separate sensors are used on the input end to provide information to determine the temperature gradient along the tube. When the gradient is used in connection with the temperature sensed at known locations at the upstream and downstream section of the tube relative to the selected location that temperature differential is used to determine the flow of fluid. The tube preferably is secured to, or embedded in, a layer of material adapted to transfer heat between sections of the tube.

Abstract: Apparatus for measuring the flow of a fluid, comprising a tube through which the fluid to be measured may flow, means for varying the temperature at a selected location of the tube and detectors for measuring the temperature in a place in the flow upstream, and in a place in the flow downstream of the selected location and means for determining the flow of the fluid from the measured temperature values, the tube being secured to, or embedded in, a layer of a material adapted to transmit heat from a section of the tube in a direction substantially normal to the tube to another section of the tube or to a heat conductor spaced apart from the tube.

Abstract: In a direction sensitive flow velocity meter for a gas or a liquid, including a sensing plate having a sensor part and a heat generating element, and an electronic circuit for processing the electric signals furnished by the sensor part, the sensor part comprises at least one Seebeck detector.