| 摘要 |
<p>PURPOSE: To shorten a time for attaining the thermal equilibrium condition of respective portions, and to improve responsiveness and measuring accuracy by setting the resistance of a heating portion to be several times or more as high as the resistance of a lead portion, and embedding one end of a heater in the interior of a heat insulating hold member. CONSTITUTION: The resistance Rh of a meander-like heating portion 3a with approximately uniform width, which is formed by providing a resistance film 3 in a range of 40 to 80% from one end of an insulating board 2 in a lengthwise direction, is five time or more as high as the resistance Rs of a lead portion 3b, which is provided continuing with the heating portion 3a as far as the other end of the board 2. Since the ratio Rs/Rh of both resistances Rh, Rh becomes small, a heating quantity flowing to fluid via a hold member 5 becomes small so that a starting time is reduced. Since an area occupied by the film 3 is large in the area of the board 2, in detecting the temperature change of the board 2 by the film 3 no response delay is allowed. Since the one end of a heater 1, one part of the lead portion 3b, an electrode portion 3c, and the like are sealed inside the member 5, the heating quantity flowing to liquid is reduced. Thereby, a time for attaining the thermal equilibrium condition is shortened so that responsiveness and measuring accuracy are improved.</p> |
