We presented some of the theory of load cells, and a novel
application of a three-ring spherical load cell in the construction
of a versatile measurement system. Internal and external
curvature of the sphere was a problem as it caused a Wheatstone
bridge imbalance which was corrected by auxiliary parallel
trimming resistance and software compensation. C++ software
was developed to show and store the compression forces
obtained by the load cell. The versatility of the load cell system
we designed permitted us to obtain data in different ways in the
application of post-harvest processing of apples and oranges.
Future work activities include the development of a new device
employing wireless sensor technology to establish cooperative
communication among the devices. This will permit more
realistic experiments when the devices will be deployed as real
fruit in a post-harvest system.