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“Shawcity’s technical expertise has provided cogent solutions to a range of gas monitoring challenges and its staff knowledge is of an order expected of university research scientists.”

Bill Parker, Helios

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Product Code: GFM436-0000-000

GFM-436 Landfill Gas Monitor (CH4, LEL, CO2, O2, H2S, CO, Hexane, PID CF, Datalogging)

The GFM436 measures the proportions of methane (by volume and LEL – Lower Explosive Limit), carbon dioxide, oxygen, hydrogen sulphide and carbon monoxide in soil gas.
Hexane content can be measured to assist in areas with hydrocarbon vapours (from spilt fuels, oils or other contaminants), and the GFM436 can also measure gas pressure (differential and static), flow rate (instantaneous and peak) and temperature.
An optional temperature sensor can be plugged in for gas temperature measurements or alternatively, a vane anemometer can measure the velocity in a gas extraction system pipeline.

*Discount available if two or more are ordered at the same time*.

The GFM436 leads in its class with many outstanding features:-

  • Measurement of 6 gases – CH4, CO2, O2, H2S, CO and Hexane.
  • The hexane measurement allows the presence of other hydrocarbons (split fuels, oils or other contaminants) to be determined.
  • Displays LEL and determines a PID (photo ionization detector) compensation factor for use with PID instruments.
  • Bidirectional measurement of instantaneous and peak borehole flow.
  • Measurement of atmospheric, dynamic differential and static pressure.
  • Optional water level data entry with 2 meter readings can be stored for each borehole location.
  • Maximum operator usability with bright LCD display, intuitive operator buttons and screen layouts and a field exchangeable battery pack offering up to 8 hours work time.
  • Easy administration with sample point label setting using Siteman PC software, manual data storage and programmable unattended data logging functions, USB data download and a CSV or AGS 3.1/4 format export facility.
  • 12 month recalibration interval.

Product available for purchase POA. Please contact a member of our team to discuss your requirements.


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ATEX is the name commonly given to the two European Directives for controlling explosive atmospheres.

ATEX certification ensures that equipment is fit for use within explosive atmospheres and is supplied with adequate information to ensure it can be used safely.

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