A new dual-gasEtO plus H2Osensor has earned CSA Approval for hazardous applications. This explosion proof sensor gives precise readouts of both gases simultaneously. Widely used for sterilization, ethylene oxide (EtO) is extremely effective, but also extremely dangerous: The gas is both explosive and toxic. To improve EtO performance, water vapor is used in the sterilization process, cutting amount of EtO used as well as actual sterilization times. By continually monitoring ongoing values of both gases, the sensor can boost efficacies and efficiencies of the sterilization process. The sensor can feed 4-20 mA output data to remote chart recorders, controllers, meters, and the like.