A vernier adjustor for a conveyor system is provided. The vernier adjustor includes first and second longitudinal members moveable in slidable relation and a pin, the first and second longitudinal members each including a plurality of slots separated by respective first and second spacings. The pin is adapted for placement within an aligned slot pairing to fix movement of the first longitudinal member relative to the second longitudinal member. The first and second longitudinal members are positionable in increments less than the first and second spacings. In particular, the first and second longitudinal members are positionable in increments substantially equal to the difference between the first spacing and the second spacing. Movement of the first longitudinal member relative to the second longitudinal member provides an incremental tensioning of an endless belt associated with the conveyor system.