Capacitive level gauge, esp. for oil reservoir on aircraft engine

摘要

The capacitances connected in a bridge network are those existing among five coaxial hollow cylinders (A1-A5). The upper inner cylinder (A1) is positioned above the max. level (Nmax) of the liq. (L) in the reservoir (R), and the lower outer cylinder (A4) below its min. level (Nmin).The lower inner cylinder (A2) and upper outer cylinder (A3) have their respective extremities at these max. and min. levels which are the boundaries of the fifth cylinder (A5) interposed between them. The liq. level (N) affects the output voltages (V1,V2) derived by the bridge from the sinusoidal input voltages (U1,U2).