Abstract: A flow sensor of the thermal type having a U-shaped sensor tube with two legs and a connecting limb with two adjoining electrical resistance elements, and with a housing. The sensor tube has an inlet side and an outlet side. The housing has a first and a second housing part of a thermally well-conducting material, each with an inner surface provided with cavities and with an outer surface. The housing parts are placed with their inner surfaces against each other, while the U-shaped sensor tube has a main surface that extends parallel to the inner surfaces. The housing parts surround the connecting limb and the legs of the U-shaped sensor tube such that the sensor tube is thermally clamped in between the housing parts in two locations: a first location situated between its inlet side and the upstream resistance element, and a second location situated between its outlet side and the downstream resistance element.

Abstract: A flow sensor of the thermal type having a U-shaped sensor tube with two legs and a connecting limb with two adjoining electrical resistance elements, and with a housing. The sensor tube has an inlet side and an outlet side. The housing has a first and a second housing part of a thermally well-conducting material, each with an inner surface provided with cavities and with an outer surface. The housing parts are placed with their inner surfaces against each other, while the U-shaped sensor tube has a main surface that extends parallel to the inner surfaces. The housing parts surround the connecting limb and the legs of the U-shaped sensor tube such that the sensor tube is thermally clamped in between the housing parts in two locations: a first location situated between its inlet side and the upstream resistance element, and a second location situated between its outlet side and the downstream resistance element.

Abstract: A mass flowmeter of the thermal type provided with a flow sensor with a flow tube through which a fluid can flow during operation, with a temperature sensor in an upstream position (A) and a heater (H) in a downstream position (B), and power control means and temperature measuring means for keeping the temperature difference between A and B at a predetermined constant value. Between A and B, the flowmeter is provided with means for preventing the temperature at A from rising owing to thermal conduction from B to A via the tube in the case of no flow or a weak flow.

Abstract: A mass flowmeter of the thermal type provided with a flow sensor with a flow tube through which a fluid can flow during operation, with a temperature sensor in an upstream position (A) and a heater (H) in a downstream position (B), and power control means and temperature measuring means for keeping the temperature difference between A and B at a predetermined constant value. Between A and B, the flowmeter is provided with means for preventing the temperature at A from rising owing to thermal conduction from B to A via the tube in the case of no flow or a weak flow.