| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide an electromagnetic flowmeter capable of largely reducing time necessary for determining emptiness of a duct even when a capacitor is provided in an AC coupling part. <P>SOLUTION: An electromagnetic flowmeter comprises: a DC component signal processing part executing emptiness detection for a duct on the basis of DC potential generated in an electrode by allowing a DC current to flow through the electrode; and an AC component signal processing part executing deposit detection by receiving, via a capacitor, an AC signal generated on the electrode by allowing an AC current to flow through the electrode. The DC component signal processing part includes electrode potential estimating means for estimating increase tendency of the DC potential on the basis of DC potential on the electrode measured at least twice at a prescribed time interval after a starting point where the capacitor has charge of zero; and duct emptiness detecting means for determining whether or not the estimated DC potential exceeds a prescribed threshold value before the capacitor is fully charged. <P>COPYRIGHT: (C)2012,JPO&INPIT |
