LIQUID LEVEL METER

• Main Authors: MORI KENICHI, MINAGAWA TADAO, YAMAZAKI ICHIRO
• Format: Patent
• Language: English
• Published: 25.05.1989
• Subjects: MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METERING BY VOLUME; PHYSICS; TESTING

PURPOSE:To certainly detect the change of a liquid level, by detecting the change of the liquid level from the change of the electric resistance of a superconductor. CONSTITUTION:A liquid level detection part 1 is constituted of a heater 2, an insulator 4 and the superconductor 3 composed of YBa3Cu3O7 formed on the insulator 4 in a film form by sputtering and a voltmeter 5 is connected to the superconductor 3. Herein, when the detection part 1 is present under the liquid level of liquid nitrogen, the heat generated by the heater 2 is removed by liquid nitrogen and the temp. of the superconductor 3 is held to critical temp. or less and the electric resistance of the superconductor 3 becomes zero and no potential is detected by the voltmeter 5. When the detection part is exposed above the liquid level by the lowering of the liquid level, the superconductor 3 is heated by the heater 2 to reach critical temp. or more and the resistance of the superconductor 3 changes from zero to several mOMEGA. By this method, the voltage between both terminals of the superconductor 3 largely changes and the change of the liquid level can be certainly detected by the voltmeter 5.