Light load roller apparatus

The utility model discloses a light load roller apparatus which comprises a U shape tray clamping groove. The middle part of the tray clamping groove is provided with a linking rod. The end part of the linking rod is perpendicularly connected with a roller guiding rod. The roller guiding rod goes beyond the central shaft of the roller. A roller bearing is arranged between the roller guiding rod and the roller. A four-corner error tolerance marking and loading device of a weight sensor is arranged behind the light load roller apparatus, which drives the tray to conveniently move to a proper position so the tray is detached from the sensor. When the tray is detached from the sensor, a workman will conveniently change for another sensor. In this way, the efficiency to sensor changing improves, which means that the testing efficiency for a sensor will be increased accordingly. With a simple structure and low cost to make, the apparatus enjoys a good anti-wearing performance, ensuring it has a long service lifetime.