It is important that the belt vibrates freely and does not come into contact with the sensor head. Therefore for belts with a heavy section the type 5 sensor is advised.

On some applications it may not be possible to gain access to both sides of the belt. The type 10 cylindrical sensor is suitable in this case as it needs only to be pointed towards one face of the belt. However, its performance in rejecting high levels of background noise is poorer when compared with the standard dual transducer sensors, and therefore it may not be suitable for some measurement situations.

The CLAVIS optical sensor is a high performance sensor which can be 'beamed' onto the belt from distances up to 75mm. It can be directed onto either the flat side of the belt or onto the edge of the belt. It is therefore suitable for applications where the belt is difficult to access. It was primarily developed for belt tension measurement on Ducati motorcycles where belt access is partially masked by the frame of the motorcycle.
Sensor Heads

The purpose of the sensor head is to detect the natural frequency of vibration of the belt. As the level of this acoustic signal is very small special patented techniques must be employed to recover this signal from the often high levels of ambient noise in a busy industrial environment. The twin transducers of the sensor head should be positioned in the centre of the belt for optimum performance. For belts up to 25mm wide the standard type 3 sensor is suitable.

For wider belts a sensor with longer jaws which enables the transducers to be positioned over the centre of the belt is more suitable.