| 摘要 |
<p>PROBLEM TO BE SOLVED: To obtain a highly reliable and durable high sensitivity flow rate measuring apparatus requiring no A/D converter by arranging a heating element and an oscillator of non-cantilever beam structure closely each other on a substrate, detecting the temperature variation of heating element due to cooling effect corresponding to the flow rate based on the variation of frequency of oscillator thereby detecting the flow rate. SOLUTION: An oscillator 2 comprises a triangular prism having non- cantilever beam structure cut out integrally from a single crystal substrate of silicon 1 by etching. The substrate 1 is trenched deep from the rear side by etching and diaphragm structure is provided at a part where heating elements 3, 3 and an oscillator are arranged. The oscillator 2 is oscillated naturally through positive feedback of oscillation detection signal to a driving resistor 4. More specifically, flow rate of fluid is measured based on the variation in the frequency of oscillator 2.</p> |
