Quality Gas Monitoring Systems for a Global Market Since 1980

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The OX-AN® brand has been at the forefront of gas detection systems and gas detection equipment for over 3o years.

OX-AN® Brownfield & Landfill Gas Detection Systems


OX-AN®’s Brownfield & Landfill Site Gas Detection Systems are designed for personnel safety monitoring in:

  • Housing Developments on Brownfield Sites
  • Retail and Office Parks
  • Sports and Leisure Sites
  • Sheltered Housing
  • Industrial Buildings
  • Public Building Developments e.g. Hospitals, Schools, Prisons

Landfill/Brownfield Site Gas Safety Detection Systems


Since 1990, OX-AN® has been providing purpose built gas monitoring solutions for buildings constructed on brownfield sites. Methane and Carbon Dioxide gases from disused industrial sites, power stations, mine workings or landfill sites may, if undetected, pose a potentially serious threat to anyone living or working nearby. It is essential that such risks be minimised by the use of continuous and accurate gas monitoring within all voids, cavities, rooms and cupboards.

The system offers a cost effective, accurate and reliable solution for the continuous sampling of potentially harmful gases from contaminated sites. The system is available for commercial and industrial buildings, and can be configured in a special outside enclosure for residential housing.

How the Landfill/Brownfield Gas Detection System works

OX-AN® Landfill Gas Safety Monitoring Systems use infrared sensors to measure the concentration of Methane and Carbon Dioxide that may be present.

Our system can monitor up to twelve spaces or compartments from a single installation. Air is sampled from each compartment through a series of solenoid valves via a highly reliable diaphragm pump on a time-shared basis.

The brown field / land fill site gas detection system is designed to operate continuously with service intervals of one year.

When a gas concentration greater than 0.5% Methane or 1.0% Carbon Dioxide is detected, the system will remain sampling from that area enabling the readings to be observed until the concentration falls or the system is reset.

The system is set to trigger the warning amber LED arrays if gas levels go above 0.5% Methane or 1.0% Carbon Dioxide and trigger the full system alarm red LED arrays and 90dB sounder should the gas levels exceed 1.0% Methane and 1.5% Carbon Dioxide.

A fast cycle override makes it possible to check the gas concentrations in all areas at three minute intervals when the need arises.

The analyser may sample air from any part of the building whether accessible or not. This is useful to detect ingress of gas through the slab by positioning the sample pipes in positions such as the mains water and electricity inlets. This is usually agreed at the planning stage with the Architects or Consultants.

Key Features of the OX-AN® Landfill/Brownfield Gas Monitoring System

  • Digital control and set-up of all functions
  • Recall of alarm events: zone, gas concentrations, date and time
  • Monitors up to 16 locations
  • Two stage alarm outputs with 3 amp volt free relays to switch on ventilation fans
  • Clear indication of fault zone on large LED display
  • Sample point isolation
  • The system does not introduce any spark risk in the monitored areas
  • Can be configured to measure under the slab without alarms
  • Print on demand function documents time stamped events

Remote Panel

Should the gas detection/monitoring system be activated by the detection of high levels of gases on a brown field / land fill site, the remote panel indicates the affected zone and whether the status is “warning” or “alarm”. This is sited in a position clearly visible from the outside (usually the foyer) and is invaluable to the emergency services who may assess the situation without entering the building.

How many sensing points do I need?

The number of sensing points required to adequately monitor a space depends upon a number of factors. Please contact us for free technical advice or a site visit.

Technical Details

Sensors: Infrared
Range: 0 – 3% Carbon Dioxide 0 – 5% Methane
Voltage: 240V a.c.
Current Rating: 5 amp
Output: 2 x 3 amp single pole changeover relays (volt free contacts)
Display: Function: 2 x 16 back illuminated liquid crystal displayZone: 2 x 1.5″ 7 segment LED displayAlarm: Matrix of 5mm red LED’sWarning: Matrix of 5mm amber LED’sArea safe: matrix of 5mm green LED’sSystem Status LED’sFault: System fault has occurredIsolated: One or more sensors isolatedMuted: Sounder is mutedSlow Cycle: System in slow cycle modePrint Pending: Event is ready to printHealthy: System is powered & functional
Warning Sounder: 90 dB @ 1 M
Mute: External momentary push button
Pneumatic Pump: Double head diaphragm pump
Zone Sampling: Normally closed solenoid valves
Sample Points: Monitors up to 16 locations
Sample Line Length: Up to 100 metres with standard pump
Enclosure Sizes: Monitor and remote panel 53cm high x 43cm wide and 20cm depth from wall

Note: Remote panels can be sited up to 300 metres from the main unit.

Further information about landfill systems can be found here

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