Abstract: A patient weighing system includes novel load sensing casters (12) or load lift modules (92) installed on a hospital bed or other patient housing device. The casters and load lift modules each include pneumatic lifts (54, 106). The lifts are operative to load and unload the weight of the device onto a piezoelectric load cells (60; 150, 152). The load cells are electrically connected to control units (14, 98) which include visual displays (16). In operation, the discharge time constants for the load cells are calculated by first raising the weight of the bed off the load cells with the lifts. Thereafter, the load is reapplied to the load cells by exhausting the air from the lifts. The control unit compensates for the short duration and decay of the sensor signals and sums the weights sensed by the load cells to determine a total weight.