Abstract: A top loading load cell mass comparator having a load cell and a cantilevered beam connected between the load cell and a weight supporting platform which is self-centering to compensate for off-center loading when moving or replacing weights on the platform. A preload compressive force is applied to the load cell to minimize hysterisis and creep error in the load cell during weight exchanges on the weight supporting platform.

Abstract: The strain gauge bridge circuit located in the load cell of a load cell mass comparator is modified to provide temperature stability by coupling a remotely located temperature compensating circuit between the two normally connected output ends of strain gauges in adjacent arms of the bridge. The compensating circuit is comprised of a pair of series connected low noise, drift free precision resistors of relatively low resistance value compared to the resistance of the strain gauges. The precision resistors are shunted by relatively high valued potentiometers which operate to balance the bridge. One potentiometer additionally includes a series connected high value precision resistor for providing fine balance while the other potentiometer is used for coarse balance.

Abstract: A load cell mass comparator wherein a pressure compensated load cell is connected at its upper end to a floating plate through a self-aligning coupling, such as, a universal joint assembly. The floating plate is slidably mounted on a plurality of guide rods extending between fixed upper and lower plates. A spring assembly and shock absorber are mounted between the upper fixed plate and floating plate. The lower end of the load cell is connected to the mass to be calibrated through a universal joint, thrust bearing, and spherical load stop bearing. The construction and arrangement of the components in the load cell mass comparator provides an instrument employed heretofore in a laboratory environment to a commercial environment where masses in the range of 1 to 10,000 pounds can be compared and calibrated.

Abstract: The strain gauge bridge circuit located in .[.the.]. .Iadd.a .Iaddend.load cell .[.of a load cell mass comparator.]. is modified to provide temperature stability by coupling a remotely located temperature compensating circuit between the two normally connected output ends of strain gauges in adjacent arms of the bridge. The compensating circuit is comprised of a pair of series connected low noise, drift-free precision resistors of relatively low resistance value compared to the resistance of the strain gauges. The precision resistors are shunted by relatively high valued potentiometers which operate to balance the bridge. One potentiometer additionally includes a series connected high value precision resistor for providing fine balance while the other potentiometer is used for coarse balance.