CAPACITANCE LIQUID LEVEL METER (VARIANTS) Russian patent published in 2007 - IPC G01F23/24 G01F23/26 

FIELD: the invention refers to the field of instrument making and designed for control of the level of dielectric and current conducting liquids in hydraulic systems (fuel, freezing, accumulative etc) for example the level of oil or cooling agent in transport vehicles.

SUBSTANCE: the liquid level meter has a two-electrode capacitance sensor with an external 10 and interior 11 electrodes electrically connected with an electronic scheme having a stabilized source of power supply, an amplifier, a generator and a trigger. According to the first variant the capacitance sensor is fulfilled in the shape of a coaxial condenser "C". The interior electrode 11 of the sensor is fulfilled tubular and is mounted inside a fluoroplastic probing rod 12. The interior electrode 11 is connected to the input of a phase comparator which is additionally introduced in the scheme and whose output is connected with input of the trigger and the output of the last is provided with a line of delay and has two outputs - direct and inverse connected with a transistor key fulfilled with possibility of fulfillment of an operation "switched on" or "switched off". At that the electronic scheme is fulfilled on a digital integrated microchip. According to the second variant the interior electrode 11 of the coaxial condenser "C" is fulfilled tubular and is additionally provided with a protective shield 22. The shield 22 is fulfilled in the shape of a spiral spring out of bronze and electrically connected with the external electrode - the body 10 of the coaxial condenser "C".

EFFECT: increases sensitiveness and accuracy of measuring of the level of liquid.

6 cl, 4 dwg