Torsion vibrator of a supersonic viscosimeter

A torsion vibrator for a supersonic viscosimeter comprising in combination a case, an electrically conductive magnetostrictive bar having an upper and a lower end, a toroidal transformer for exciting said magnetostrictive bar, said magnetostrictive bar being connected with the case at its upper and by an upper coupling and at its lower end by a lower coupling, and passing through said toroidal transformer, a lower magnetostrictive resonator mechanically connected to the lower end of the magnetostrictive bar and extending freely from said case, an upper magnetostrictive resonator connected to the upper end of the magnetostrictive bar extending through said case, said magnetostrictive bar, said upper and lower couplings and said case combining to form the secondary winding of said toroidal transformer, and a pick-up coil located within said case and surrounding the upper magnetostrictive resonator.