The Guardian Plus range of infrared gas monitors from the Sensors Division of Edinburgh Instruments (Edinburgh Sensors) provides the high accuracy detection and measurement capabilities required for the continuous monitoring of methane (CH4) or carbon dioxide (CO2) in landfill gases or biogas. Proprietary dual wavelength non-dispersive infrared sensor technology with built-in temperature correction ensures reliability, accuracy and long-term stability with the additional benefit of low maintenance costs.
This versatile range of wall mounted monitors offers detection level ranges of between 0-3000 parts per million and 0-100% by volume and there are two user-adjustable set points with audible and visible alarms triggered if the measured concentration strays outside the set points. An integral pumping system allows gases to be sampled from up to 30 metres away from the monitor. Gas concentration is displayed on a clear 4 digit LCD.
The monitor is housed in a tough, IP54-rated plastic enclosure. Safety features include dual hydrophobic filters to protect the sensors from the ingress of particulates and from contamination if water is drawn into the instrument with the gas. In addition, a flow sensor triggers an alarm if the gas flow rate through the unit becomes too low for proper operation.
A variety of user-selectable analogue signal outputs are available for remote monitoring and datalogging. These include 0-20 mA or 4-20 mA linear or non-linear outputs.