Patent ID: 8049878

Claim:
A method of detecting defects in a ceramic filter body having a honeycomb structure with first and second ends and an array of longitudinal channels between the first and second ends and having respective first and second channel ends, the method comprising: positioning adjacent the honeycomb structure first end a first light source unit having multiple first light source elements that generate respective first light beams; positioning immediately adjacent the honeycomb structure second end a first detector unit having multiple first detector elements per channel end for at least one first channel, so that the first light source and the first detector elements are capable of being in optical communication through the corresponding at least one first channel; transmitting at least one of the first light beams from the first light source unit to the first detector unit through the at least one first channel; detecting first light from the at least one of the first light beams with the multiple detector elements per channel and, in response thereto, generating at least one first electrical detector signal representative of a gray-scale variation in the detected first light for the at least one first channel; and processing the at least one first electrical detector signal to determine if at least one first defect exists within the at least one first channel.