PCT No. PCT/GB86/00625 Sec. 371 Date Jun. 3, 1987 Sec. 102(e) Date Jun. 3, 1987 PCT Filed Oct. 16, 1986 PCT Pub. No. WO87/02458 PCT Pub. Date Apr. 23, 1987.A rheometer having relatively movable shearing elements (4,5) for imposing shear forces on a sample of material placed between such elements, is provided with heating means comprising an induction heating coil (18) heated to permit induction heating of the elements (4,5) during use.