DUAL ENERGY X-RAY TECHNIQUE FOR FOOD PROCESSING MEASUREMENTS

WE PROPOSE TO EXPLOIT DUAL ENERGY X-RAY MEASUREMENT TECH- NIQUE TO QUANTITATIVELY DETERMINE THE PRO PORTIONS OF TWO DIFFERENT MATERIALS IN A FOOD PROCESSING LINE AT CONVEYOR BELT SPEED. THE MAIN PROBLEM WITH A SIMPLECONVENTIONAL X-RAY INSPECTION SYSTEM IS THAT IT REQUIRES KNOWN MATERIAL THICKNESS BETWEEN THE X-RAY SOURCE AND DETEC-TOR ARRAY. OFTEN IT IS VERY DIFFICULT TO OBTAIN KNOWN OR DEFINITIVE FOOD MATERIAL THICKNESS WITHOUT MAKING THE TASTE OR APPEARANCE OF THE FOOOD UNACCEPTABLE TO THE CONSUMER. THEDUAL ENERGY MEASURING SYSTEM WOULD OVERCOME THE REQUIREMENT OF KNOWN MATERIAL THICKNESS. IF THE ATTENUATED X-RAY INTEN-SITY IS MEASURED AT TWO DIFFERENT AND WIDELY SEPARATED ENER-GIES, THEN THE COMPOSITION VARIATIONS IN MATERIAL CAN BE DE-TERMINED EVEN IN THE PRESENCE OF UNKNOWN MATERIAL THICKNESS ESSENTIALLY, THE TWO INDEPENDENT MEASUREMENTS ARE USED TO CALCULATE TWO UNKNOWNS ONE OF WHICH IS MATERIAL THICKNESS WHILE THE OTHER MATERIAL COMPOSITION VARIATION. WE PROPOSE TO DEVELOP A DUAL ENERGY X-RAY INSPECTION SYTEM USING TWO SETS OF DETECTOR ARRAYS. THE FRONT ARRAY OF DETECTORS WOULDDETECT LOW ENERGY SPECTRA FROM AN X-RAY SOURCE. THE BACK DETECTOR WOULD BE EXPOSED TO X-RAYS AFTER THEY HAVE PASSED THROUGH THE LOW ENERGY DETECTOR. THUS, THE SPECTRA. THE DETECTORS WOULD BE FABRICATED IN MULTICHANNEL ARRAYS, SIMIL-ARTO THE ONE USED IN CT SCANNERS.