When using belt weigh scale,there will often be zero drift phenomenon.Generally,this phenomenon is mainly composed of internal and external factors.The main internal reason is that the key originals of belt weigh scale such as:weighing sensor,speed sensor,weighing instruments and so on.The external reason will be analyzed from the stress situation of belt weigh scale,such as the belt deviation,radial runout roller,called fouling degree holder. Next,we will explain the specific reasons for zero drift in detail.

一、 The internal factors:
1、There is stained materials on the conveyor belt,so after shutdown every day,you need to clean the accumulate materials on the conveyor belt,and ensure that the conveyor belt is clean;
2、The aging of the weighing sensor leads to the output signal instable or error,resulting in zero instable;
3、The failure of some electronic measuring element results in the zero drift of belt scale;
4、The output of speed sensor is instable or the speed of conveyor belt is unstable,changes larger;
5、The instrument exists measurement error,generally appear in long time and the aging instrument;
6、There is dust and plot materials on the weighing bridge of belt scale,not only will affect the zero drift of belt scales,but also seriously affect the measurement accuracy of belt scale;
7、The belt tension is uneven;
8、The load sensors overload severely.

二、The external factors:

1、The temperature characteristics of the materials and the long using of the belt result in the elongation of the belt;
2、If there is deviation of the belt,it will cause the partial load of belt scale,so that the output of the sensor is unbalanced,then the stress of belt scale will change,which results in zero drift;
3、The materials or debris stuck in the weighing bridge;
4、The distance of conveyors is too long,if the distance between the loading and unloading port of conveyor is too long,the tension of the belt will change greater,so the stress of belt scale would become unstable,resulting in zero drift;
5、There is dust and plot materials on the weighing bridge of belt scale,not only will affect the zero drift of belt scales,but also seriously affect the measurement accuracy of belt scale;
6、The weighing sensors overload severely.

The above two are the reasons for zero drift for belt weigh scale,so we need to keep in mind the emergence of these internal and external factors in the process of using belt weigh scale,nip in the bud,of course,the routine maintenance is also inseparable.