PS250 User Instructions
scale, the display would show "OL",means overload. You should
remove the objects, and reopen again.
2.3 [TARE/ZERO]
In weighing mode, if the object's weight is less than the 4%
capability of the scale, when you press [TARE/ZERO]button, the
scale would return ZERO;
In weighing mode, if the object's weight is more than the 4%
capability of the scale, when you press [TARE/ZERO]button, the
scale would reduce the tare.