Measuring method for liquid level of glass melting furnace and liquid level sensor to be used in the method

The present invention provides a method of measuring a liquid level of molten glass in a glass melting furnace to be used for solidifying high level radioactive liquid wastes with glass and a sensor therefor. Namely, a plurality of thermocouples are disposed vertically alternately in a plurality of rows each at equal distance in the vertical direction at least in the vicinity of the liquid level of the molten glass of the molten glass vessel. In addition, a cooling pipe is disposed for introducing coolants for cooling the inside of the case. The temperature of each of the plurality of thermocouples is detected to measure the liquid level of the molten glass based on the difference of the temperature caused by presence or absence of the molten glass. It is not necessary to form an additional vessel for measuring the liquid level according to the present invention. Since the thermocouples are disposed while taking the arrangement into consideration, the measuring accuracy can be improved. (I.S.)