Abstract: An apparatus for the opto-electrical determination of a measured value or magnitude at a viscosimeter, especially at a rotational viscosimeter, wherein there is provided a rotatable body immersible in the medium to be measured and connected with the rotor of a motor and a shaft fixably connected for rotation with the stator of the motor and pivotably mounted against the action of the restoring force of a torsion spring. In order to obtain a series of light pulses which are independent of the measured magnitude and to also obtain a further series of light pulses dependent upon the measured magnitude, at least one reflector rotatably driven by a motor about an axis of rotation is arranged in spaced relationship from and essentially axially parallel to the pivotably mounted shaft which itself is equipped with a reflector and a stationary optical block or system is dispositioned in an appropriate geometric arrangement with respect to the rotatably driven reflector.

Abstract: A system for measuring the longitudinal or angular displacement of a movable component with respect to a reference position, wherein an increment scale track is supported at a scale carrier affixed to the component, and associated therewith are stationary increment-reading means, an increment counter and electrical circuits for counting properly with respect to the direction of motion of the component the algebraic sum of the increment units traversing in front of the increment-reading means. The scale carrier supports at a second scale track parallel to the increment scale track a multiplicity of absolute-value marks, each of which is spaced from the next following mark by a particular spacing characterizing the absolute value of its distance to the reference position, and which spacing is counted in increment units.