| 摘要 |
<p>PURPOSE:To reduce the size and cost and obtain high accuracy by arranging an orifice at the upstream side of a heat generating resistor, and molding piping, the orifice part, and the storage part for the driving circuit for the heat generating resistor of synthetic resin in one body. CONSTITUTION:Fluid enters the orifice 7 through the piping 1 which forms a main passage and is jetted there to fly across the heat generating resistor 2. In this case, the diameter of the orifice 7 is so set that the Reynold's number is, for example, >=3,000 at a minimum measured flaw rate, and then the flow of the fluid becomes stable only in a turbulent flow area. Therefore, long piping length is not necessary and the size is reduced, and the piping 1, orifice 7, and driving circuit storage part 9 are formed of a synthetic resin material, i.e. electric insulator with small heat conductivity, so a supporting conductor 3 is embedded directly without interposing any insulating bush and the influence of variation in ambient temperature upon the temperature of the heat generating resistor 2 is ignored.</p> |
