METHOD FOR MEASURING LIQUID LEVEL OF CONDUCTIVE LIQUID

PURPOSE:To reduce a measuring error and to measure a liquid level at a place isolated from a measuring place, by covering the surface of a conductor with a film of an electric insulating substance and applying voltage between the conductor and an electrode body in a conductive liquid. CONSTITUTION:A covered body 1 wherein a conductor 2 is covered with a film 3 composed of an electric insulating substance having a thickness (t) and an electrode body 4 composed of a conductor are provided in a conductive liquid 5 and voltage is applied between the conductor 2 of the covered body 1 and the electrode body 4. When it is assumed that the contact resistance of the electrode body 2 and the conductive liquid 5 can be neglected, since the conductor 2 and the conductive liquid 5 are opposed to each other so as to be separated by the thickness (t) of the film 3, they form a capacitor having the conductor 2 and the liquid 5 as both electrodes. When the thickness (t) is constant, the capacity of the capacitor is proportional to the area of the electrodes, that is, the contact length of the covered body 1 and the liquid 5. Therefore, the proportional formula of the electric capacity of the capacitor and the contact length of the covered body 1 and the liquid 5 is empirically calculated and the electric capacity is measured to be applied to the proportional formula to make it possible to calculate the contact length of the covered body 1 and the liquid 5.