| 摘要 |
<p>PURPOSE:To measure the flow velocity of a fluid using heat stably without the influence of a difference in the thermal diffusivity and thermal conductivity due to the difference of a fluid and contamination of a temperature detecting portion. CONSTITUTION:A heat generating portion 28 is provided on the wall of a passage 2. A temperature detector 1 is provided downstream from the portion. An electric current is applied to the heat generating portion 28 to be heated during a short time, and the operation of detecting the output peak of the temperature detector 1 is repeated plural times with a fixed waiting time. The flow velocity is obtained by calculation from the output frequency of the temperature detector. If there is periodic noise, plural waiting times are selected at random, and the flow velocity is obtained from each waiting time and the output frequency of each time.</p> |
