| 摘要 |
<p>PURPOSE:To perform precise flow rate detection at low cost by embedding a semiconductor flow rate detecting element which has a temperature measuring element and a heating element on the same semiconductor board in the wall of a tube wherein fluid flows. CONSTITUTION:The semiconductor flow rate detecting element 1 which has the heating element and temperature measuring element formed on the same semiconductor substrate and a semiconductor temperature detecting element 5 which measures the temperature of the fluid are embedded in the wall surface of the tube 4 where in the fluid flows. A driving circuit detects the temperature of the fluid by the detecting element 5 and the temperature of the flow rate detecting element by the measuring element 6 and controls the heat generation of the heating element 7 so that the flow rate detecting element 1 is a specific temperature higher than the fluid at any time; and the current, potential, or voltage of the driving circuit which varies according to variation in flow rate is detected. The detection output is processed by a signal processing circuit and outputted to a display device, flow rate controller, etc. Consequently, the flow rate is detected with high precision at low cost.</p> |
