Probe for measuring the level of a liquid

A probe of the mutual inductance type with a linear response which is independent of temperature comprises a rigid support, two insulated cables disposed in interengaged relation and wound on the support, means for supplying one of the cables C1 with alternating current having constant amplitude and frequency, and means for measuring the voltage between the two extremities of the second cable C2. A single resistor R is placed between the extremities of the cable C2, the resistance value of the resistor and the value of the frequency f being determined so as to ensure that the variations in voltage measured between the extremities of the cable C2 are reduced to zero in respect to any given level of liquid outside the probe. The probe was designed for measuring the level of liquid alkali metals in nuclear reactor vessels