Abstract: A viscometer provided with a transducer for converting a viscosity parameter of a fluid into an electrical signal. The transducer comprises a container, provided with a cavity for the fluid to be measured, a support element firmly connected thereto and an oscillatory device, which at one end is firmly attached to the support element and at the other end has an oscillatory body. An oscillation drive coil powered by alternating current and a constant magnetic field device for generating a constant magnetic field are provided for bringing and maintaining the oscillatory body in oscillation. The transducer is provided with a detection device for detecting the oscillation of the oscillatory body. The constant magnetic field device is arranged such that it is not able to come into contact with the fluid to be measured and the constant magnetic field lines generated by said device are directed towards the oscillatory body.