Thermal fluid flow apparatus

A device for measuring the flow rate of a fluid, the device comprising:

• a measure cell having at least one fluid flow inlet and at least one fluid flow outlet and providing a fluid flow path between the inlet and outlet;
• a heated or cooled measure element arranged in the measure cell so as to be exposed to heat transfer effects of fluid flowing through the fluid flow path;
• a heated or cooled reference element arranged in the measure cell so as to have reduced exposure to fluid flowing through the fluid flow path compared to the measure element, wherein the measure and reference elements are symmetrically or equivalently arranged within the measure cell such that they experience an equivalent heat transfer environment, other than the heat transfer effects due to fluid flowing through the fluid flow path;
• at least one measurement component connected to at least one of the measure element and the reference element, for measuring at least one parameter that is indicative of the heat transfer effects of fluid flowing through the fluid flow path;
• and
• means for deriving a signal indicative of the fluid flow rate from the at least one measured parameter.