ELECTRIC MEASURING INSTRUMENT Russian patent published in 1998 - IPC

FIELD: electrical engineering. SUBSTANCE: capacitive transducer is formed by pointer indicator and immovable electrodes made of current-conducting material applied on scale. Electrodes are insulated electrically from both scale and remaining members of instrument construction. System of immovable electrodes is essentially one or several concentric arc- shaped layers with center on pointer rotational axle. Layers are separated from one another by grooves. Every layer is divided by radial grooves oriented relative to scale marks into several sectors combined electrically into two electrodes so that adjacent sectors of layer refer to different electrodes. Every electrode of every layer is connected to separate auxiliary terminal. Pointer position on scale is determined by means of capacitive transducer. Its output parameters indicate layer electrodes above which pointer is located. Since radial grooves separating the electrodes are oriented relative to scale marks, position of pointer on scale may be determined. Due to differential structure of variation of every layer output capacitances, use may be made of highly sensitive bridge circuits for their conversion. EFFECT: enhanced measurement accuracy. 4 dwg