LIQUID LEVEL MEASURING METHOD AND DIFFERENTIAL PRESSURE TRANSMITTER

PROBLEM TO BE SOLVED: To provide a liquid level measuring method capable of determining the interface position, and a differential pressure transmitter therefor, when a pressure in a sealed tank storing two kinds of fluids with each having different density as measuring objects is changed, and the densities of the measuring objects are changed. SOLUTION: This liquid level measuring method has characteristics wherein a pressure on the low-pressure side in the sealed tank, with two kinds of fluids having each different density as the measuring objects are stored is measured; the differential pressured between the pressure on the low-pressure side and the pressure on the high-pressure side in the sealed tank is measured; and the position of the interface between the fluids is determined based on the pressure, each density of the measuring objects determined by a pressure stored beforehand, the distance between upper and lower surfaces in the sealed tank, and the differential pressure. COPYRIGHT: (C)2008,JPO&INPIT