Attitude error self-correction for thermal sensors of mass flow meters and controllers

A thermal mass flow measurement system comprising:

• at least two thermal sensor coils mounted on a tube through which a fluid flows along a common axis of flow for use in generating a flow measurement signal representative of the flow of fluid through the tube, wherein (a) one of the coils is adapted in provide thermal energy to the fluid flowing through the tube at an upstream location so as to establish and measure the upstream temperature of the fluid at the upstream location, and one of the coils is adapted to measure the downstream temperature of the fluid at a downstream location, and (b) the flow measurement signal is a function of the difference between the measured upstream and downstream temperatures;
• a gravity sensor fixed relative to the thermal sensor coils and constructed and arranged so as to measure the force of gravity in the direction of the common axis;
• and
• a signal modifier that modifies the flow measurement signal as a function of the measured force of gravity so as to compensate for attitude sensitivity of the thermal sensor coils.