Abstract
Industrial sensor studies often report controlled defects or isolated field events without preserving the commissioning evidence that connects them. This retrospective single-site study evaluates an optical conveyor-belt monitoring system through technical assessment, industrial and belt-loop tests, control-system integration, six investigation groups, and one field-confirmed edge tear. The installation used upper and lower optical camera subsystems with embedded processing, proprietary internal confirmation logic, industrial communication, and connection to the plant programmable logic controller (PLC). Repeated passages of the same defects were treated as non-independent descriptive observations. Among the quantified configurations, scenario-specific descriptive PLC-output proportions ranged from 20.0% for an approximately 0.20-mm nearly closed central slit to 96.0% for a 6-mm V-shaped opening. Fourteen protection-output assertions were assigned to six investigations. Corrective observation preceded re-interlocking on 7 August. On 31 October, the edge-tear indication reached the configured protective-stop state and caused an automatic conveyor stop; inspection confirmed the edge tear, and maintenance repaired the belt. The case demonstrates why camera-interface recognition, confirmed output, plant action, and field confirmation must be reported separately. Internal optical calculations, confirmation parameters, software implementation, configuration details, and decision logic remain proprietary.