US Patent 7373722 Device for measuring package size

A package measurement apparatus comprising three measurement devices, one for each dimension. Each measurement device comprises a plurality of signal receptor modules. Each module comprises a row of signal receptor, and a signal energy source. In a first calibration step, the outputs of each receptor are standardized to reference maximums and minimums. In a second calibration step, calibration sets of receptor outputs are created and recorded. During measurement, a measurement set of receptor outputs is obtained and matched with a calibration set of receptor outputs to determine the dimension of an object.