FLOW DIRECTION GAUGE

PURPOSE:To enable the production of a high-sensitive and high-precise guage which is reduced in the occurrence of trouble, by a method wherein a heater for heating a fluid and a temperature-measuring sensor, which is heated by a fluid heated by the heater, are placed in an appropriate manner. CONSTITUTION:A heater 1 for heating a fluid and 2 pairs of temperature-measuring sensors 2, 2' and 3, 3' are securely attached to a base body 4. A protruding length of a heating part 1' of the heater 1 is longer than those temperature-measuring parts a-d of the temperature-measuring sensors. The heater is connected to a power source 5, and the temperature-measuring sensors are coupled to a measuring part 9. All the temperature-measuring parts of 2 pairs of the temperature-measuring sensors are positioned at equal spaces from the heater, and are located on straight lines which cross each other at right angles at the heater positioned on a point of intersection. If the fluid flows in the directions of arrow marks A ad A', the temperature measuring parts at the upstream and the downstream of the heater differ in temperature. If an output voltage, corresponding to said temperature difference, is generated, a ac direction and a bd direction component of a flow are obtained. The ratio of the output goes to a tangent of an angle theta of the flow direction to the ac direction.