| 摘要 |
<p>PURPOSE:To obtain a fluid velocity sensor which is rigid, high in sensitivity and fast in response speed wherein an orientation of a placed apparatus need not be considered by placing a thin film temperature measuring resistor 2 at the tip of a slip plate of a heat insulating printed board. CONSTITUTION:When a fluid velocity sensor is placed in fluid to be measured, a heat dissipation amount from a first thin film temperature measuring resistor 2 which has generated heat according to the velocity changes. That is, by an increase/decrease of the fluid velocity, temperature of the resistor 2 rises or drops, while a resistance value increases/decreases according to the change in the temperature so that voltage between electrode terminals 14, 15 increases/decreases. On the other hand, an ambient temperature is detected by a second thin film temperature measuring resistor 3. Current is made flow to the resistor 2 so that a difference between temperature detected without air flow and the temperature by the resistor 2 is maintained always constant to compensate change in the ambient temperature. The voltage value of the resistor 2 thus obtained is subjected to numeric conversion whereby output voltage V which is proportional to a fourth-power root of a value of fluid velocity (v) of an equation can be obtained. The resistor 2 is placed at the tip of a strip branch part 11 to prevent a relation of the equation from largely being out by disturbance.</p> |
