| 摘要 |
<p>PURPOSE:To equalize a temperature distribution in a membrane type resistance by making the upstream side larger than the downstream side with regard to a resistance value per unit area of a membrane type resistance pattern for feeding back a calorific value so that a temperature of the membrane type resistance provided in a suction passage becomes constant. CONSTITUTION:As for a membrane type resistance 6 provided in a suction passage, its calorific value is fed back, it is controlled so that a temperature of the membrane type resistance 6 becomes constant, and an air flow rate is detected from an impressed voltage. A resistance value per unit area of the upstream side of an air current of the membrane type resistance 6 is made larger than a resistance value per unit area of the downstream side. For instance, a resistance wire 61 having the same thickness is placed closely, or a sectional area of the resistance wire 61 is made small, by which the resistance value per unit area of the upstream side is made large. In this way, a temperature distribution in the membrane type resistance 6 is equalized, the time required for being balanced is shortened, and the responsiveness is made high in its speed.</p> |
