Stepwise level measurement arrangement - uses simple circuit contg. groups of capacitors with subgroups of parallel capacitors and digital comparison unit

摘要

The arrangement for stepwise level measurement contains capacitors (71-1..72-4,81-1..82-2) arrranged along a fill section with capacitance values affected by a dielectric formed by the fill material. The capacitors are arranged in one or two groups (70,80), each with two sub-groups (71,72;81,82) of parallel capacitors. Each two capacitors of a group in succession in the vertical direction and in the same dielectric have approximately the same capacitance and belong to different sub-groups. The sub-groups of a group are connected to a common comparator unit which forms a digital comparison signal according to the difference in the sub-group capacitances. At least some capacitors of one group are arranged for interpolation between those of the other. The group-wise digital signals form binary locations of an output signal. ADVANTAGE - Contains simple circuitry and exhibits long-term output signal stability.