Development of the backscattered intensity integral imaging technique for the detection of micro-channels in shelf-stable food packages

Hermetically sealed flexible food packages require a very effective seal integrity test to guarantee the quality of thermally processed food. In this contribution a new ultrasonic pulse-echo technique called Back-scattered Intensity Integral (BII)-mode imaging for the detection of microchannel defects in these types of food packages is proposed and evaluated. The BII technique integrates the received backscattered signal of each A-line and produces an integrated spatial map, a BII-mode image. It has been shown that the BII-mode image has the ability for subwavelength detection of channel defects. For example, that a 10 μm-diameter channel defect can be detected at a center frequency of 15 MHz (λ≈140 μm)