The AT-MGS-550 advanced gas detector can utilise any combination of sensor technologies, including electrochemical, semiconductor (MOS), catalytic bead or infrared, in a single platform for unparalleled detection capability. It meets ASHRAE 15 and EN 378 requirements. The AT-MGS-550 leak detector combines electrochemical, semiconductor, catalytic bead and infrared sensors into one platform to support leak detection for the new low GWP (Global Warming Potential) refrigerant blends as well as natural refrigerants to enable gas leak detection in the often harsh environments of industrial refrigeration. The AT-MGS-550 can easily be integrated into any building management system (BMS). The Modbus RTU interface allows the user to program and configure the unit remotely through the BMS. Remote access gives complete control to the user when using Modbus. Alternatively, electrical current or volt analogue output provides an industry standard reading using 4-20mA. Having three integrated relays within each instrument reduces the need for having to wire alarm devices back to a central control system. Because of the integrated relays, the AT-MGS-550 can be operated as a stand-alone system. Each relay can be individually programmed to trigger alarm devices and actions separately or as a redundant system. The straightforward menu structure is identical regardless of the type of sensors used, reducing the costs and amount of time for training required upon installation or during maintenance. The AT-MGS-550 offers the flexibility of adding a second sensor at any point in time without the need for any additional controllers. Any sensor can be remotely mounted from the main instrument to a distance of 5 meters. It meets the requirements of EN 378 and ASHRAE 15.