| 摘要 |
<p>PURPOSE:To attain miniaturization and the enhancement of measuring accuracy, by forming a membrane like heat generating resistor on an insulating substrate and further adding a temp. compensating resistor. CONSTITUTION:Both of a heat generating resistor 6 and a temp. measuring resistor 7 are parallelly arranged in the same minute substrate 1 and that part of the substrate 1 in the vicinity of the resistor 6 is locally removed by etching and both resistors are thermally insulated by an insulating layer. A pair of the resistors 6, 7 are arranged in a flow passage 10 through which a fluid flows so as to position the resistor 6 in the upstream side. Both resistors are respectively connected to electric resistor elements 9, 10 to constitute a bridge. The resistor 7 is controlled along with the resistor 6 by a feedback circuit so that the temp. difference between them and a fluid is always kept constant even if the temp. of the fluid such as oil flowing through the flow passage 10 changes. A transistor 12 is turned ON and a current supplied from an input terminal 13 is supplied to the resistor 7 to generate heat and the temp. of the fluid is measured by the resistor 6.</p> |
