Abstract: In a temperature-control device for samples, in particular for NMR spectroscopy, comprising a vessel (20) provided with an opening (19) for receiving a measuring sample (1), an inlet opening (10) for introduction of the fluid, an outlet opening (15) for the outflow of the fluid and a flow channel (18) through which at least a partial flow of the fluid is guided past the sample (1), as direct fluid flow, from the bottom to the top, there is provided at least one by-pass channel (17) which is arranged in such a way that an additional partial fluid flow can be guided past the upper area of the said sample (1) in the form of a by-pass fluid flow (7). This enables also the upper area of the sample (1) to be temperature-controlled in an efficient way so as to minimize the temperature gradient in the sample (1).

Abstract: An apparatus is employed to compensate for time-variant field interference in magnetic fields of electromagnets with high field homogeneity, in particular in specimen areas of superconductive electromagnets for measurements of magnetic resonance. The magnetic field that permeates a specimen area of the electromagnet is identified by means of at least one induction coil, a voltage induced in the induction coil is supplied to a control stage, and a compensating current that flows through a compensating coil that surrounds the specimen area is set by means of an output signal from the control stage. In order to be able to compensate for remote interference emanating from far outside the magnet, at least one compensating coil and at least two induction coils, or vice versa, are disposed.