Greisinger gco 100 icarbon monoxide measuring meter greisinger gco 100 p the greisinger gco 100 is a carbon monoxide meter that will detect dangerous gases and warns the user both visually and acoustically where the co emissions exceed the allowable occupational exposure limit or tlv mak p p the gas concentration is measured at the end face opening of the sensor device the co meter comes supplied with a calibration certificate p p applications control and maintenance of heating s