| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To facilitate diagnosis in trouble such as disconnection in a heat generating resistor and a temperature detecting resistor. <P>SOLUTION: This flow measuring instrument is provided with a means for driving the heat generating resistor at constant temperature by the heat generating resistor and a temperature compensation resistance, a means for arranging the temperature detecting resistors in both sides of the heat generating resistor to detect a flow rate based on a temperature difference between the temperature detecting resistors, a means for impressing a bias voltage to one of bridge circuits constituted of the temperature detecting resistors, a means for varying an off-set voltage in response to a current of the heat generating resistor, and a digital output regulating means (zero span circuit means) for amplifying the temperature difference between the temperature detecting resistors to acquire a fixed output characteristic. The diagnosis is facilitated in the trouble such as the disconnection in the heat generating resistor and the temperature detecting resistor, and reliability is secured for the whole air flow measuring instrument, as effects thereof. The characteristic is easy to be corrected to enhance performance, in some of the digital regulating means, as another effect. <P>COPYRIGHT: (C)2004,JPO&NCIPI</p> |
