Abstract: In a torsional oscillation apparatus, for example for testing plastics, a lower clamp is arranged in torsionally-fast or non-rotating manner, for one end of a test specimen, and an upper clamp is provided for the other end of the test specimen. The upper clamp is connected securely to the underside of an oscillatory body suspended from a thread or wire which is twistable in a substantially resistance-free manner. A tautening device exerts, on one of the clamps, a force which keeps the test specimen taut. A stimulating device provides stimulating torsional oscillations of the torsion pendulum formed by the test specimen and the oscillatory body, and a transducer, cooperating with the oscillatory body, produces electrical pulses corresponding to the torsional oscillation of the pendulum.

Abstract: A device is described for the torsional testing of test bodies which avoids reference to the zero point of oscillation and, accordingly, is independent of zero point shifts. The device is of the type wherein a torsional pendulum can be made to undergo damped torsional oscillation and has a transducer for producing a potential corresponding to torsional oscillation. The duration of oscillation between two reversal points of the oscillation and also the damping are measured by the use of an electrical circuit including first, second, third and fourth series circuits. Each circuit includes a condenser and half-wave rectifier and the circuits are connected in parallel through switches to a transducer. Each rectifier is connected to an auxiliary circuit which, when a potential arises in the blocking direction of the rectifier, supplies a signal to a control circuit.