The pipe flow enthalpy difference meter serves to determine the variation of enthalpy flow rates between two flow cross sections in liquid pipe flows, especially in cases of small temperature differences of the order of about 1#xA0;K. Although the flow rate is being measured by an appropriate commercial magnetoinductive flow meter, a precise temperature difference sensor based on the well-known Seebeck effect for thermopiles was designed and constructed for the determination of the bulk temperature difference. Despite the fact that the thermopile consists of 40 thermocouples connected in series, the sensors are located in a pipe cross section of merely 21#xA0;mm in diameter, and are fit for application in ionized and slightly corrosive liquids. The output signal of the thermopile amounts to 1.6#xA0;m V/K, so that a temperature difference of 1#xA0;K can be measured with an accuracy of #xB1;1 (#xB1;0.01#xA0;K) by means of an appropriate voltage meter under laboratory as well as under field conditions
展开▼
