| 摘要 |
PURPOSE:To detect the residue of a liquid accuretely by applying a specified voltage to a self-heating type thermistor provided at the liquid level detection position through a resistance with a specified resistance value to compare the terminal voltage of the thermistor with the reference value. CONSTITUTION:A thermistor 5 is arranged as a liquid level sensor at the liquid level detection position for detecting the residue of a liquid in a container 1 and a lead of the thermistor 5 is drawn outside the container 1 with an insulated pipe-shaped tube 6. The thermistor 5 is sealed into a glass bead about 2mm. in the diameter and employs a self-heating type which is heated by a Joule heat consumed in the resistance itself. This is used at several tens mW or more and detects the liquid level utilizing changes in the resistance value due to the difference of the temperature between that 5 in the liquid 2 and that in the air. |
