PURPOSE: To prevent saturation of an amplifier due to electric noise induced in electrodes when liquid flow stops to dry the upper surface of a weir and raise the impedance between electrodes by providing a weir at the inner bottom of a measuring pipe and electrodes at the elevation over the upper surface of the weir.
CONSTITUTION: Liquid goes into an arc shape capillary 6a provided along with the inner bottom surface of a measuring pipe 1 and the lower periphery of a weir 3 in the direction of circumference of the measuring pipe 1 and a capillary 6b prolonging from the middle of the capillary 6a to the upstream of the weir 3. If the flow stops, the liquid goes up in the capillary 6a owing to the surface tension of the liquid and the bottom ends of electrodes 2, 2 touch the liquid. Thus, the impedance between the electrodes is kept low.
YOSHIDA YUTAKA
FURUKAWA MASAAKI
AMADA YOSHITAKA
