| 摘要 |
<p>PURPOSE:To miniaturize a flow rate measuring apparatus by forming at least some of a reference resistor, the first resistor and the second resistor into a resistor group wherein a plurality of series connection bodies each formed by connecting a switch and a resistor in series are connected in parallel. CONSTITUTION:Among a reference resistor RR, the first resistor RA and the second resistor RB, the second resistor RB forms a resistor group consisting of resistors RB1-RBn and a switch is connected thereto in series and, when the value of the difference between the temp. of the heater and the circumferential temp. is high, the value of the difference between the heater temp. and the circumferential temp. is changed over according to a flow rate by turning the switch ON/OFF. By this method, a wide range of a flow rate from a low flow rate to a high flow rate can be measured while the output sensitivity of a sensor is changed without requiring a plurality of sensors and a flow passage and, therefore, a flow rate measuring apparatus can be miniaturized.</p> |
