SWG100 BIOGAS – Biogas Analyser

The SWG100 BIOGAS is a fixed gas analyser for continuous monitor of O2, CH4, CO2 ,H2S and H2 gases with-in biogas applications.


The SWG100 BIOGAS is a biogas analyser which provide continuous monitor of 02%, CO2%, CH4%, H2S, H2 and CO gases primarily in Biogas generated from large and medium AD (Anaerobic digestion) and Biomethane plants.

Choosing the correct Biogas Analyser.
Eurotron Instruments offers 2 additional models of BioGas Analysers:

  • If your application involves installations in WWTP ( Waste Water Treatment Plants) or Landfil sites, the SWG100 BIOEX, ATEX ZONE II certified gas analyser will be a better solution. Please click this link
  • If your application involves installations for small size farm based anaerobic digesters and you only require 1-2 sampling points and not a continuous monitor system then please visit the SGW100 BIOCOMPACT page .

Continuous monitor system.
The SWG100 BIOGS analyser continuously measure O2, CO2%, CH4% and H2S which means that it detect gas changes as they happen. In some processes, the quality of the biogas changes quickly and CHP’s Gas Engines require a live signal to adjust to these changes.

Built-in Gas Cooler.
The SWG100 BIOGAS integrated gas cooler, along with the peristaltic pump and the AUTO CAL functions provide high accuracy, repeatable and stable readings in any process conditions even with extreme wet gases, such has biogas sampling before the heating treatment. The employment of the gas cooler also maximise sensors protection from moisture build-up in the gas stream.

H2S Innovative Dilution system 50:1 

The optional dilution system installed on the H2S channel is proven to be essential in many applications where H2S can fluctuate from very low ppm to very high concentration. This innovative system allow to continuously measure H2S in any process condition whilst protecting the sensor from sudden rise of H2S levels. Typical applications include sampling before and after the scrubbing using a multi-sample point gas analyser.

Data logging and Industrial Interfaces.
Measured data are displayed on its large colour display and automatically logged to the internal SD card with user definable interval period. Data outputs are available via Modbus RTU, 4-20 mA analogue outputs ( up to 40 individually configurable)  and most of the common industrial interfaces such us Profbus, Ethernet and Profinet.
In addition to all this, the SWG100 BIOEX can provide up to 20 alarm relay outputs, fully configurable, which are trig by a user define above/below value. Typical application include CHP’s engines Oxygen trip/protection.

Plug & Play Sensors.
The plug and play pre-calibrated sensors technology allow the user to replace all the sensors on site in just under a couple of minutes, dramatically reducing the downtime of the gas analyser. Additional features such as the over-write available on the analogue output minimise CHP’s engine disruption in case of analyser malfunctioning.

Service Contract.
Eurotron Instruments UK limited offer an extensive range of onsite service contract tailored made to suits the requirement of each customers.


The SWG100 BIOGAS offers many features and benefits with an excellent price/specification ratio.

  • Purpose built fixed gas analyser
  • Accurately measure 02, CO2%, CH4% as standard
  • Additional measurements for H2S, H2, and CO
  • H2S sensor protection via solenoid valve and purge pump
  • Dual H2S sensors for low and high levels
  • 1-10 Sampling points
  • Integrated Peltier Gas Cooler and condensate  pump for automatic moisture removal
  • Continuous monitor as standard
  • Auto Calibration function as standard
  • User Calibration function
  • Up to 40 x 4-20 mA outputs and inputs, individually configurable
  • Gas Analyser system alarm and gas alarms/notification
  • Up to 20 alarms contact relay outputs
  • Standard Modbus RTU digital communication
  • Optional Profibus, Profinet and Ethernet industrial interfaces
  • Data and event logging on SD card
  • Optional Cabinet Heater for cold climate operation
  • Exceptional on-site service support from our specialized team of engineers


The SWG100 BIOGAS is currently installed in many sites across the UK and it is becoming the preferred choice of many AD plants and CHP engines suppliers. The SWG100 BIOGA fixed Gas Analyser main applications include:

  • Large & Medium scale AD plants
  • Biomethane
  • CHP Engine protection


Sample Points 1-10
Gas Range Accuracy∗ Resolution Type Method
O2% 0-25 % ± 0.2% Vol 0.01% Vol EC Continuous
CH4% 0-100% ± 0.3% Vol 0-10 %
± 0.5% Vol 10-65 %
± 1.5% Vol 65-100 %
0.01% Vol NDIR Continuous
CO2% 0-100% ± 0.3% Vol 0-10 %
± 0.5% Vol 10-65 %
± 1.5% Vol 65-100 %
0.01% Vol NDIR Continuous
H2S 0-4000 ppm ± 5 ppm 1 ppm EC Continuous or  Sample
H2S 0-50 ppm ± 5 ppm 1 ppm EC Continuous or Sample
H2S 0-200 ppm ± 5 ppm 1 ppm EC Continuous or Sample
H2S 0-10.000 ppm ± 50 ppm 1 ppm EC Continuous or Sample
H2 0-1 % ± 20 ppm 1 ppm EC Continuous
CO (H2 compensated) 0-20000 ppm ± 20 ppm 1 ppm EC Continuous
Barometric Pressure 850-1150 mbar  n/a 1 mbar  Piezo Continuous
Calculated Values CV gross/net 0-50 MJ3, MJ/Kg
Display 3.5″ TFT color display, backlight
Keyboard Tactile with password protected menu
Output communications/Industrial Interfaces
Analouge up to 40 x 4-20 mA outputs/input individually configurable
Alarms 1 x system alarm and up to 20 alarms relay output , free contact 24 VDC/5A
Digital Modbus RTU as standard, optional Ethernet, profinet, profibus DP and wed enable remote access
Data logging Internal memory and SD card
Event Log Record of Alarm/event to SD card
Gas Sample
Gas Inlet Stainless steel gas gas fittings with 1/8″ ID Thread
Gas Cooler Integrated high efficiency gas cooler with condensate pump for moisture removal
Filter Teflon Particulate filter, internal housing in Viton
Flow 40-60 l/hr
Pressure Sample pressure from -100 to 300 mbar
Internal Gas Leak detector ( optional)
Standard Ventilated cabinet with continuos fan monitoring
Standard Stainless Steel flow orifice restriction
 Sample Gas Shut-down solenoid valve
Dimension 700x600x210 (H x W x D) wall mounting ( bracket supplied)
Weight App: 25 KG
Case Material Special coated Aluminium
IP Protection IP 54
Operating Temperature +5 to 45 °C ( -10 to 45 °C with optional heater)
Heater Optional Cabinet Heater 200 W
Mains/Power Universal 100-240 VAC/ 47..63 Hz, 90W -( 300 W with cabinet heater)
Notes ∗ After Calibration and do not include calibration gas accuracy
∗∗ Specifications might change due to product improvement with-out prior communication


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SWG100 BIOGAS – Biogas Analyser