Patent Number: 
Section: abstract

Provided is a apparatus for sensing a liquid level reliably based solely on an analog process even if a liquid held in a container boils, causing the liquid level to fall. A liquid level sensing apparatus includes: a probe selection unit configured to select a probe whose heater is to be activated from among the plurality of probes; an input unit configured to receive an output of the temperature sensor of the probe selected by the probe selection unit, the output being received as a temperature signal directly in the form of an analog quantity; a signal processing unit configured to output a processing signal of the temperature signal in synchronization with activation of the heater; a calculation unit configured to arithmetically process the temperature signal and the processing signal and output a result; a gas/liquid discrimination unit configured to discriminate whether the detecting point exists in a gas phase or a liquid phase based on the output result of the arithmetic processing; and a display unit configured to indicate a discrimination result produced by the gas/liquid discrimination unit.