The new Sentry IT (Information Technology) gas sensor transmitter modules offer a broad array of features, including:

• Integral LED display
• Integral alarm relays for High, Low and Trouble
• SMC Sentry bus interface
• 4-20 mA output
• Modbus RTU serial interface
• Remote sensor configuration
• Optional control relay pack
• Visual menu system for configuration of alarm setpoints, calibration, maintenance and alarms acknowledge
• Designed and approved for installation and operation in hazardous areas

The FM Approved 5100-28 IR Gas Sensor Module utilizes Non-Dispersive Infrared technology to monitor for combustible gases (Methane and others). Output range is either 0-100% of LEL (default) or percent (%) by volume. This Module requires minimal maintenance with a calibration check once a year. Internal continuous self-diagnostics will automatically indicate any fault or optics problems.

Infrared technology has the benefits of:

• Reduced need for calibration and thus lower operating costs.
• Operates in high combustible gas and/or low oxygen environment
• Can operate in environments where catalytic bead poisons might exist
• Rapid recovery after exposure to high concentrations of hydrocarbon gas (exceeding 100% LEL)

Most combustible gases absorb infrared light energy at defined wavelengths, providing an absorption signature for that gas. The principle of an infrared detector is based upon the absorption of the infrared light at a specific wavelength as it passes through the gas. The more of the absorbing gas that is present, the more light is absorbed. The detector measures the energy from an infrared light beam at a wavelength that is absorbed by the gas and compares it to the energy emitted by the source. The difference in energy received by the detector indicates the level of gas in the atmosphere