GFM 426

  • GFM 426
  • GFM 426
  • GFM 426
  • GFM 426

The GFM426 is an ATEX certified landfill gas analyser providing fast and accurate measurements of gas and pressure.

It is a fixed configuration that measures 5 gases, using a combination of IR and EC channels. It also provides three different pressure measurements: Atmospheric; Static (Gauge); Differential. Flow rate is derived from a calculation using differential pressure.

Optional extras to measure velocity and temperature are available.

Eliminate the need for manual data collection and reporting with Siteman Software – a powerful tool developed in-house specifically for the GFM range. Siteman allows users to collect, analyse and store data, making an essential tool for anyone working on-site.

To download the Siteman Software, please complete the Software Download form.

  • Ex. Rating: EEx ib IIB T1
  • Provides measurements of up to 6 gases
  • Measure atmospheric, static, and differential pressures
  • Calculated flow rate reading through differential pressure
  • Small and portable – easily fits in one hand
  • SiteMan PC software included
  • High-contrast LCD display
  • User-swappable battery pack
  • Battery life ranging from 8 to 12 hours and 4 hours charging time
  • Charger suited to client’s country
  • Protective, weather-proof leather case
  • Supplied in ready-to-go site kit
  • Manual and unattended data-logger with USB download

All GFM instruments require annual service and recalibration and service.


Range Comparison Datasheet User Manual Siteman Manual


Download EX Certificates

Product FAQs

  • What is a GFM 426?

    The GFM 426 is an ATEX, IECEx and UKEx rated instrument designed to measure gas, pressure, and high flow rates from landfill sites.

  • What us the difference between the GFM 426 and GFM 436?

    Both instruments are designed to measure landfill gases, pressures, and flow rates. The key difference is the flow capacity of the instrument. Both measure the key gas components of CH4, CO2, O2, H2S and CO, both measure Atmospheric and Differential Pressure, and both have data logging and recording functionality.

    The GFM 426 will calculate flow using differential pressure, measuring difference in pressure between 2 spots either side of an orifice plate within an extraction system. The calculation shows flow rate in normal metres cubed per hour (Nm3/hr). By comparison, the GFM 436 measures flow rate in litres per hour (I/hr) using an electrical component within the instrument. Fore more in-depth comparisons, please view our GFM comparison chart.

  • How do I order my GFM 426?

    Before enquiring about the GFM 426, please do take a look at the instrument datasheet to ensure the product is fit for purpose.

    If you have any further queries, reach out to your distribution or the manufacturer for support. Orders can be placed through Gas Data’s distribution partners. Please do make clear the model you are enquiring about from the start.

  • How do I carry out monitoring with a GFM 426?

    When purchased, you will receive the following with the GFM 426:

    • Instrument
    • Sample Pipe
    • Battery Charger
    • Spares Pot
    • Allen Key
    • USB drive with operation manual

    This is referred to as the “ready-to-go site kit”. All instruments are shipped fully charged and are able to be deployed upon arrival with little to no set-up required.

    The sample pipe provided is ~1m in length and includes a dust trap filter to prevent particulates from entering the sensor and causing damage. The male connector will attach to the inlet manifold of the instrument, and, on the opposite end, the silicon 1/4” tube will connect to most industry-standard sampling points. For in-depth instructions on how to operate the instrument, please view the manual file stored on the received USB drive.

  • How often does my GFM 426 require servicing?

    The GFM 426 requires an annual service and calibration. Please contact your supplier to organise service in good time prior to the calibration date – this is shown on the latest calibration certificate and on the home screen of the instrument.

  • How do I book a service?

    It is highly recommended to book a service in advance of the instrument’s calibration date. Reach out to the distribution partner you have purchased the instrument from to receive a service slot. Servicing typically takes 10-15 working days, with collection and reshipment being included in the service cost.

  • What is the lead time on a GFM 426?

    The GFM 426 is built to order to match the gas and pressure expansion configuration determined by the customer. This, inevitably, will affect the lead time. Instrument lead times can range between 2-14 weeks – please to your order acknowledgement for a live lead time.

  • How do I order/consumables for my GFM 426 ?

    Identify the part you require and contact the distribution partner from whom you purchased the analyser. Alternatively, visit the Gas Data website and fill in the enquiry form associated with consumables and spares.

  • Where can I use the GFM 426?

    The GFM 426 can be configured to whichever gases you require from the list of available sensors (please re-fer to datasheet for these). From there, the instrument’s ATEX rating means it can be used in Zone 1 areas. The full certification is: EEx ib IIB T1.

    Please review your risk assessments to ensure that the instrument has the correct certification for use in your application.