| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To reduce an increased error while maintaining a centrifugation effect of a roundabout section in a secondary channel. <P>SOLUTION: In an air flowmeter employing a roundabout structure on the upstream side of a heating resistor in the secondary channel, a step 105 is disposed near an exit part of the secondary channel as shown in Fig.1-a. Therefore, the channel resistance in the secondary channel is increased, and such the characteristic is obtained that the higher the flow rate is, the slower the flow velocity is in the vicinity of the heating resistor. According to this effect, the pressure loss in the secondary channel can be changed while maintaining the function of the centrifugation by disposing the step on the downstream side of the heating resistor, thereby improving its pulsation characteristic. Therefore, a pulsation error can be improved without impairing any inertial force of roundabout channels. <P>COPYRIGHT: (C)2008,JPO&INPIT</p> |
