GFM 436

  • GFM 436
  • GFM 436
  • GFM 436
  • GFM 436

The GFM436 is an ATEX certified gas analyser for site investigation, landfill gas control, and environmental regulation compliance monitoring.

It is a fixed configuration, measuring the proportions of CH4 (by both volume and Lower Explosive Limit), CO2, O2, H2S and CO presented in soil gas, greenfield and brownfield sites. This includes land affected by landfill operations or other industrial contamination.

Additionally, hexane content is measured to assist in areas with hydrocarbon vapours from spilt fuels, oils, or other such contaminants. This instrument has the additional capacity to measure gas pressure (differential and static) and flow rate (instantaneous and peak).

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.

Alternatively use our new software, Instrument Connect available on our Software page: Software & Data Portal – Gas Data

  • Ex. Rating: EEx ib IIB T1
  • Provides measurements of 6 gases
  • Measures flow rate, atmospheric, static, and differential pressures
  • 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 your country
  • Protective weather-proof leather case
  • Supplied in a ready-to-go site kit
  • Factory-calibrated infrared sensor for measuring Hexane vapour
  • Detector (PID) correction factor for low levels of Volatile Organic Compounds (VOC)
  • Bi-directional measurement of instantaneous and peak borehole flow
  • Storage of 2 water level readings from DIP meter taken at each borehole
  • 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 436?

    The GFM 436 is an ATEX, IECEx and UKEx rated instrument designed to measure gas, pressure, and high flow rates. The GFM 436 is deployed for environmental compliance monitoring, brownfield contamination monitoring, and landfill gas control.

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

    Both instruments are designed to measure landfill gas, 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 436 measures flow rate in litres per hour (I/hr), using an electrical component within the instrument. By comparison, the GFM 436 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 meters cubed per hour (Nm3/hr). Fore more in-depth comparisons, please view our GFM comparison chart.

  • How do I order my GFM 436?

    Before enquiring about the GFM 436, 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 distributor or the manufacturer for support. Orders can be placed through Gas Data’s distribution partners. Please do make clear the model you are enquir-ing about from the start.

  • How do I carry out monitoring with a GFM 436?

    When purchased, you will receive the following with the GFM 436:

    • 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.

  • What is the lead time on a GFM 436?

    The GFM 436 is built to order. Instrument lead times can range between 2-14 weeks – please to your order acknowledgement for a live lead time.

  • How often does my GFM 436 require servicing?

    The GFM 436 requires an annual service and calibration. Please contact your supplier to organise ser-vice 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.

  • How do I order spares/consumables for my GFM 436 ?

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

  • Where can I use the GFM 436?

    The GFM 436 can be configured to whichever gases you require from the list of available sensors (please refer 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.