a power shovel for surface mining operations is equipped with a suspended load measuring system . the slm system determines the net weight of the material in the shovel bucket by sensing the electrical parameters of the drive motors . a microprocessor inputs the drive motor electrical parameters and processes them according to the known geometry of the power shovel . to meet the requisite accuracy of ± 2 % for a load measuring system to be effective , the slm system utilizes a dynamic model which accounts for both conservative and nonconservative dynamic effects prevalent in power shovel operation . correction are included for the conservative effects of the rotational inertia of the drive motors and reduction gear train , the stretch of the cables , and the inertia of the bucket . non - conservative losses due to friction , gear loss and motor inefficiency are also compensated for . during truck loading operations , the slm system maintains a cumulative total of the net weight of material in the truck based on the individual weights of each shovel bucket load . the total weight in the truck is then displayed to the power shovel operator so that the truck can be accurately loaded to full capacity .