heat exchange

The temperature of a transducer sensitive element, as a result of its heat capacity, will always lag behind the temperature of the gas flow if this temperature changes. When measuring the flow temperature that varies in time, the transducer doesn't follow the changes in temperature immediately because its sensitive element temperature changes after some time. The distortions of the transducer readings are caused by the thermal inertia due to non-stationary heat processes in the transducers, as well as between transducer and the environment.

The main types of errors which occur while measuring the temperature of gas flows, including flows of fuels, are determined by the conditions of thermal balance at the interaction of the sensor of the temperature transducer (TT) with the gas flow via convection, radiation and conduction. The limited TT capacity to track flow temperature variation should also be taken into consideration. For high gas flow speeds (over 50 m/s), another type of error (the so-called speed error) arises from the transformation of part of kinetic energy of the flow into thermal energy.