LIQUID LEVEL CONTROL DETECTOR Russian patent published in 2008 - IPC G01F23/00 

FIELD: physics; measurement.

SUBSTANCE: invention is related to instrument-making, namely, to discrete detectors of liquid level control and may be used in systems and instruments for control of liquid fuel level, in storage, fuelling and also in process of operation of engines that work on cryogenic fuel under rigid mechanical impact. Liquid level detector contains casing with printed circuit board, point sensitive element (thermistor) on substrate installed on printed circuit board, which is arranged in the form of narrow thin plate, one side of which is rigidly fixed to casing base, and at the edge of opposite non-fixed side, opening is provided with diameter that is 2...4 times more than width of substrate located above the opening and made from thin heat-insulating material, additionally three point thermistors are used, two of which are installed symmetrically on the front side of substrate at the distance of not more than 0.5 mm from the edge of substrate, and the other two - underneath on the opposite (screen) side with error of alignment that does not exceed 50 micrometer. Besides, in liquid level detector, substrate with thermistors passes through opening on printed circuit board, in which contact sites and connection conductors are installed, providing serial connection of thermistors installed one under another on substrate.

EFFECT: higher fast action and accuracy of liquid level detection, higher accuracy of liquid level change rate, both in case of fuelling and draining.

2 cl, 1 dwg