Patent attributes
An engine assembly includes an internal combustion engine and a carbon monoxide (CO) sensor unit. The CO sensor unit includes a CO sensor controller including a CO sensing circuit configured to detect a level of CO and a shutdown circuit. The shutdown circuit is configured to receive a detected level of CO and calculate a trailing window average of the detected level of CO. The trailing window average includes an average of the detected level of CO over a predetermined sampling window. The shutdown circuit is further configured to determine whether to initiate a shutdown of the internal combustion engine based on at least the calculated trailing window average and a predetermined trailing window average threshold and initiate the shutdown of the internal combustion engine based on determining that the trailing window average exceeds the predetermined trailing window average threshold.