| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a thermal flowmeter in a simple structure capable of precisely measuring a flowrate of fluid within a stationary flow rate region, even an excessive flowrate out of the stationary flowrate region. <P>SOLUTION: This thermal flowmeter comprises a heating means for raising temperature at a portion in the vicinity of a pair of temperature sensitive elements provided in a sensor chip by a prescribed level rather than temperature of a fluid flowing along the sensor chip, a first flowrate computing means for obtaining the flowrate of the fluid according to a temperature difference detected by the pair of temperature sensitive elements, a second flowrate computing means for obtaining the flowrate of the fluid according to drive energy of the heating means, and an output control means that outputs the flowrate obtained by the second flowrate computing means instead of one obtained by the first flowrate computing means when the flowrate obtained by the first flowrate computing means exceeds a flowrate threshold. <P>COPYRIGHT: (C)2009,JPO&INPIT</p> |
