| 摘要 |
<p>PURPOSE: To provide a mass flow sensor which has high sensitivity even in a minute flow and is suitable for mass production by improving the detection sensitivity. CONSTITUTION: A mass flow sensor comprises a substrate 7 formed by a material having a small thermal conductivity such as glass or ceramics, and thin film thermally-sensitive elements 1a, 2a, 1b, 2b which are formed on both surfaces of the substrate 7 and paired on the respective surfaces, wherein the paired thin film thermally-sensitive elements 1a, 2a, 1b, 2b include thin film thermally-sensitive elements 1a, 1b disposed on the upstream side with respect to the flow direction B of a fluid to be detected, and thin film thermally- sensitive elements 2a, 2b disposed on the downstream side, the thin film thermally-sensitive elements 1a, 2a, 1b, 2b are heating elements and temperature measuring resistors, and the thin film thermally-sensitive elements 1a, 1b of the same upstream side and the thin film thermally-sensitive elements 2a, 2b of the same downstream side are disposed on the opposite sides of a Wheatstone bridge.</p> |
