Mass flowmeter
AssigneeBerkin B.V.
InventorsJoost Conrad Lötters, Hendrik Jan Boer, Wybren Jouwsma
Life of this patent
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Abstract
Mass flowmeter comprising a hollow conduit of a heat-conducting material for transporting in a determined flow direction a fluid with a mass flow rate to be measured, a first temperature-sensitive resistor element at a first position in thermal contact with this conduit for supplying heat to said fluid, a temperature sensor and measuring and control means connectable to the resistor element and the temperature sensor, wherein the temperature sensor is provided in thermal contact with the conduit at a second position upstream in relation to said first position, and the measuring and control means are adapted to maintain a constant difference in temperature at said first and second positions.
Claims28
Mass flowmeter comprising:
- a hollow substantially U-shaped conduit of a heat-conducting material having inlet and outlet parts for transporting in a determined flow direction a fluid with a mass flow rate to be measured;
- a heat exchanger co-acting with said inlet and outlet parts;
- a first temperature-sensitive resistor element at a first position in thermal contact with the conduit for heating the fluid at the first position when power is supplied to the heater;
- and
- a temperature sensing means arranged on, and in thermal contact with, the conduit for measuring a difference in temperature between fluid at the first position and fluid at a second position upstream with respect to the first position,
- the first resistor element being adapted for connection to a control means for controlling the power supplied to the first resistor element so as to maintain the difference in temperature at a constant level,
- the mass flow being determinable from the power supplied to the first resistor element, and
- the flow meter having a such thermally symmetrical construction that the occurrence of a temperature gradient between the first and the second position when no power is supplied to the first resistor element is substantially prevented.
Dependencies are inferred from the claim text.