| 摘要 |
<p>PURPOSE:To decrease the thermal disturbance or the flow resistance to a fluid, and also, to decrease the measurement error simply and at low cost by measuring a time difference by which the temperature variation or the pressure variation of the fluid heated by a heating means passes through two points of the downstream side. CONSTITUTION:When a current is allowed to flow to an induction heat coil 2 by pulse discharge from a pulse power source, part of a piping 1 is heated, and the temperature of a fluid flowing through the inside of the piping 1 rises. Also, propagation speed of a temperature variation of a liquid can be put so as to be equal to a flow velocity by taking a distance L between two points A, B to a value which can disregard a temperature rise in the longitudinal direction caused by thermal conduction of the piping. As a result, a flow velocity (v) can be given by v=L/t2-t1=L/DELTAt by putting as t2-t1=DELTAt. In this regard, t1 and t2 denote the time when a temperature variation of the fluid is generated. Subsequently, when the flow velocity (v) is measured, temperature and pressure of the fluid can be measured by a thermometer 5 installed between A and B and a pressure sensor attached to the tip of a connecting tube 6, and a material value in its state can be known.</p> |
