Flowmeter of the Coriolis type

Coriolis mass flowmeter with a Coriolis tube and with an optical detection device, which optical detection device comprises at least one optical sensor for generating a signal that is representative of the movement of the Coriolis tube, said optical sensor comprising a light source and a photosensitive sensor, wherein the optical detection device comprises means for applying a constant voltage across the photosensitive sensor during operation independently of the current generated by the photosensitive sensor in response to incident light, as well as means for determining the value of the current generated by the photosensitive sensor and converting it into an output signal