for weights in the range x res and the counterbalance weight 46 is bottomed out in its range for load values at or below the residual value x 0 for loads in the critical range x rcw the action of the spring 50 determines the deflection of the lever 40 as shown in fig9 a virtual load bearing point 58 is shown on the counterbalance weight lever 40 to the right of the pivot 42 at the position shown the scale is at or below the residual weight and the counterbalance weight 46 is fully descended the beginning of the critical weight range i e the value x 1 is characterized by the right end of the lever 40 being descended into contact with the stopper 48 the weight values where these occur depends on the size of the weight 46 and its position along the lever 40 and also on the position of the pivot 42 these depend to some extent as well on the stiffness of the spring 50 and its tension thus the customer or user can field adjust the scale 10 to adjust the weight values in which an alarm or warning is received as shown in fig1 the sensor element for this weighing scale can be a potentiometer 56 here of the rotary type with a rotor stem 60 for moving the rotary wiper of the potentiometer the rotor stem 60 has attached to it a potentiometer lever arm 62 whose distal end is coupled to a mover element 64 on the lever 40 so that the potentiometer rotor stem 62 follows the up and down motion.