APPARATUS FOR MEASURING AND INDICATING LIMITING LEVEL OF LIQUID OIL IN NON-TRANSPARENT CONTAINERS Russian patent published in 2012 - IPC G01F23/26 

FIELD: physics.

SUBSTANCE: apparatus has electrically connected self-exciting high-frequency pulsed crystal oscillator based on a transistor, a measuring circuit having a transistor 1 amplifier, a sensor with measuring electrodes connected in the measuring circuit on which is deposited a coating which insulates from the external medium, diodes 2, 3, a measuring device and a power supply 4. The measuring electrodes used are capacitor electrodes in form of inductance coils 5, 6. All inductance coils are wound using a copper wire on insulating bases using a double-wound technique in one layer, wherein two windings of each inductance coil are connected in parallel. The apparatus also has a diode 7 connected in the measuring circuit, wherein the diode 7 is reverse connected and is connected to the collector and base of the transistor 1 amplifier of the measuring circuit. A three-stage direct current amplifier 8 made from transistors 9, 10, 11, and a diode voltage stabiliser 12 are connected to the power supply 4. The diode voltage stabiliser 12 is connected in the conventional (reverse) manner of reference diodes (stabilitrons). The measuring device used is a light indicator made from a light-emitting diode 13, which is connected to the collector of the transistor 11 of the third stage of the direct current amplifier 8.

EFFECT: wider range of use with simultaneous increase in accuracy of measuring the limiting value and simple design.

1 dwg