Spring loaded tensioning device. The force required to deflect a span length by a given amount is related to the tension in the belt. The tensiometer measures that deflection. It can be used on v-belts, banded belts or synchronous belts.
Proper belt tensioning is one of the most important factors for satisfactory operation and long service life. Too little tension will result in slippage, causing rapid belt and sheave wear. Too much tension can result in excessive stress on the belts, bearings, and shafts.