Designed to calibrate large Semi-Span balances, the Large Load Rig has been recently recommissioned. The controller, data acquisition system and computer were upgraded. The hydraulic system was completely rebuilt and numerous safety features were implemented. The versatility of the system was demonstrated when a torque tube was calibrated to very demanding loads: 800,000 in-lb of torque along with 200 lbs of thrust.
The LLR applies load to the balance via hydraulic actuators linked to precision load cells with flexures on each end of the load chain. The loads are applied in sequence per the load schedule that is selected in the operators program. The load condition is maintained within a close set tolerance level. The balance and each axis are manually realigned to an orthogonal position for each load prior to taking the data point.
The LLR is able to apply smaller loads for lower range balances. The load cells and flexures are changed to match the load range of the balance, by matching the load range for each balance the machine is able to provide increased resolution and accuracy for a wide range of balances and instrumented stings.