| 摘要 |
<p>PURPOSE:To reduce the average manufacturing cost of a module and to prevent different kinds of modules from being mixed in the manufacturing process by making a circuit module of a common design common to a body having a plurality of different main flow passages. CONSTITUTION:A hot wire element 2 is heated electrically and put in the air flow, thereby constituting a circuit to hold the temperature of a bridge circuit to be constant using the element 2 as one resistance of the bridge circuit. The flow rate is detected from the change of the generating amount of heat due to the change of the current velocity in the vicinity of the element 2. The center of an insulating module 11b is set at the axial center of a main flow passage and, a sub flow passage 5 is formed by selecting a circular area of 1/3-1/2. the diameter of the main flow passage. The length of an insulating mold 11a is unified. Accordingly, a circuit module 4 is made common, thereby reducing the cost.</p> |
