| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a diagnostic mechanism capable of diagnosing whether jamming occurs in a main flow path or a sensor flow path when a thermal flow sensor is used. <P>SOLUTION: A diagnostic mechanism 200 for diagnosing abnormality in a flow sensor 2 for measuring a flow rate of fluid flowing through flow paths 7 and 8 includes: a flow rate control part for controlling a degree of opening of a flow rate control valve provided on the flow paths so that a measured flow rate value output by the flow sensor 2 becomes a target flow rate value; a verification value output part for outputting a verification value that is a value relating to time integration of the measured flow rate value in a diagnosis period that is at least part of a period from when the flow paths 7 and 8 are closed upstream from the flow sensor 2 until when a state where the measured flow rate value is substantially equal to the target flow rate value ends; and a diagnosis part for comparing the verification value with a pre-set indicated value to diagnose whether or not the abnormality in the flow sensor 2 exists. <P>COPYRIGHT: (C)2012,JPO&INPIT |
