| 摘要 |
<p>PURPOSE: To appropriately correct temperature dependency of characteristics curve of a flow rate sensor. CONSTITUTION: A sensor element 6 is positioned in a medium flow 51, and comprises a frame 8 and a thin film 7. On the thin film 7, a heater 1, temperature measurement feelers 2 and 3 and a heater temperature feeler 4 are assigned, and on the frame 8, a medium temperature feeler 5 is provided. The temperature difference between the feelers 2 and 3 is a measurement unit for a flaw rate of passing medium. The temperature change in medium causes unbalance of a bridge arm provided with a feeler 5, at that time, thanks to adjustable resisters 21 and 24, arbitrary dependency can be selected. The temperature dependency between the heater 1 and the medium 51 is represented by TH=a0+ a1*TM+a2*TM<2> , and coefficients a0-a2 are bigger than zero. This is a desired dependency which causes an optimum temperature compensation for a sensor characteristics curve against the medium temperature TM of the heater temperature TH. The dependency has slight non-linearity, and is two-dimensional polynominal approximately having a positive coefficient.</p> |
