초록 ▼

The invention relates to a device for measuring the flow of a medium e.g., a gaseous medium or a fluid medium, which device is based on measuring and affecting the temperature distribution of a medium flowing along, which flow sensor comprises two object, each comprising a heating element and a temp

The invention relates to a device for measuring the flow of a medium e.g., a gaseous medium or a fluid medium, which device is based on measuring and affecting the temperature distribution of a medium flowing along, which flow sensor comprises two object, each comprising a heating element and a temperature sensor, the measured temperature difference being kept, by way of a control loop, to the value of zero, the asymmetry of the power supply to the objects in order to comply with the aforesaid criterion, according to which the temperature difference must be zero, being representative of the value to be measured of the medium flow, taking into account parameters associated with the medium, such as its density and specific heat.

대표청구항 ▼

1. A device for measuring a physical parameter of a medium, said device comprising:two measuring objects spaced apart at a predetermined distance, each one of said two measuring objects comprising a dissipator arranged in thermal contact with a flowing medium whose physical parameter is to be measur

1. A device for measuring a physical parameter of a medium, said device comprising:two measuring objects spaced apart at a predetermined distance, each one of said two measuring objects comprising a dissipator arranged in thermal contact with a flowing medium whose physical parameter is to be measured; a single control circuit for bringing a temperature difference between said two measuring objects repeatedly towards zero, said circuit including means for determining which one of said two measuring objects is a colder measuring object and means for supplying electric power to said dissipator of said colder measuring object until said colder measuring object is a hotter measuring object and thereafter supplying electric power to said dissipator of an other one of said two measuring objects which is now the colder measuring object until said other one of said two measuring objects is the hotter measuring object; means for determining the electric power supplied to each of said two measuring objects during at least one heating cycle; and means for calculating the physical parameter based on a ratio of the electric power determined from each of said two measuring objects.