The Z Gard S Sensor is designed to detect the presence of carbon monoxide gas, nitrogen dioxide, or refrigerants in air. All Z Gard S Sensors are available with two output versions, a 4-20 mA analog output or an addressable RS-485 digital signal. The Z Gard S Sensor with RS-485 digital output is specifically designed to operate with any Z Gard C 485 Controller, operating as a system. The Z Gard S Sensor with 4-20 mA can be installed as a stand-alone sensor typically integrated with the Z Gard C Controller or common commercial equipment including PLC, DCS or building automation systems.