Surveying device (1) for the running parameters of railway contact bearings (2) which is provided with a rotating race (3) and a non-rotating race (4) which are coaxial to a rotation axis (A) of the railway contact bearing (2) itself, the device (1) being provided with a sealing shield (5) which is mounted onto the non-rotating race (4); and which is also provided with a sealing lining/covering (7) which is integral with the shield (5), and which is in contact with a sliding surface (11s) which is in turn integral with the rotating race (3): the device also being provided with a signal generating element (15) which is integral with the sliding surfaces (3s) (11s) themselves and which is arranged inside the shield (5); and which is also provided with a sensor (16), which faces the generating element (15) in order to read the signal itself, and which is itself integral with the shield (5) in a position which is outside the railway bearing (2).