A sensor detects one or more hazardous materials, such as by measuring the concentration of one or more hazardous gasses. The sensor or an external system can also determine a location of the sensor. This location can be associated with the measured data from the sensor at the external system or at the sensor. The location could be determined at the sensor using GPS or RFID. The location could be determined at the external system using RFID. The external system can use the measured data and the location information to perform a wide variety of tasks, such as mapping hazardous materials in a processing or other environment or identifying trends in the concentration of the hazardous materials.