LIQUID LEVEL DETECTION METHOD AND LIQUID LEVEL DETECTOR

摘要

PURPOSE: To provide a liquid level detection method for making clear failure occurrence causes when detecting a liquid level by differing an output signal level when detecting the presence or absence of a liquid from that when the liquid level detector fails or is connected improperly. CONSTITUTION: In a liquid level detection method where a corresponding detection signal is outputted from a light emitting element 12 according to the presence or absence of a liquid in an optical path between the light emitting element 12 and a photo detector 14, the output signal level when detecting the presence or absence of the liquid differs from that when a liquid level detector fails or is connected improperly, thus making clear the causes of occurrence of failure when detecting the liquid level.