SWG100 BIOEX - Fixed Gas Analyser ATEX certified

The SWG100 BIOEX is an ATEX ZONE-2 certified gas analyser for continuous monitor of O2, CH4, CO2 ,H2S and H2 gases with-in the Biogas, Biomethane, landfill and Water Treatment  industries.


The SWG100 BIOEX is the NEW generation of fixed gas analysers which provide continuous monitor of 02%, CO2%, CH4%, H2S, H2 and CO gases primarily in Biogas generated from AD (Anaerobic digestion) and Waste water treatment plants, landfill gas and bio-methane upgrade plants.

ATEX Certification

The SWG100 BIOEX is ATEX certified for use/installation in ZONE II –  II 3G Ex ec nC IIC T6 Gc

Built-in Gas Cooler

The SWG100 BIOEX 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.

Robust and Easy to service

The SWG100 BIOEX design build incorporates an IP 65 rated stainless steel enclosure, extreme easy installation and full on-site maintenance and easy access of all the parts. 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.

ATEX Certification- ZONE II

The SWG100 BIOEX is a fully ATEX certified Gas Analyser for installation in ZONE II.  II 3G Ex ec nC IIC T6 Gc. To view the certificate please select the tab “download”

Easy Remote firmware upgrades

Users can easly upgrade to the latest firmware release by simply download the latest firmware from our web page and upload it to the analyser via SD card.


The SWG100 BIOEX is currently installed in many sites across the UK and it is becoming the preferred choice of many Utilities Companies and landfill operators. The SWG100 BIOEX  Gas Analyser main applications include:

  • Landfill
  • WWTP ( Waste Water Treatment plants)
  • Biogas and AD plant
  • Biomethane
  • Coal Mine ( AMM)
  • Gas Flaring
  • CHP Engine protection


The SWG100 BIOEX offer many features and benefits with an excellent price/specification ratio.

  • ATEX ZONE-2 certified by Bureau Veritas
  • 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
  • 1-4 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 24 x 4-20 mA outputs and inputs, individually configurable
  • Gas Analyser system alarm and gas alarms/notification
  • Up to 12 alarms contact relay outputs
  • Standard Modbus RTU digital communication
  • Optional Profibus, Profinet and Ethernet industrial interfaces
  • Data and event logging on SD card
  • IP 65 weather proof stainless steel cabinet
  • Optional Cabinet Heater for cold climate operation
  • Exceptional on-site service support from our specialized team of engineers


Sample Points 1-4
Sensor Technology O2 Electrochemical Cell (EC) or Paramagnetic Sensor (PM)
CH4 & CO2 Fully compensated dual channel Infrared Bench
H2S Electrochemical Cell (EC)
H2 and CO Electrochemical Cell (EC)
Gas Range Accuracy∗ Resolution Sensor Type Method
O2% or 0-25 % ± 0.2% Vol 0.01% Vol EC Continuous
O2% 0-25 % ± 0.1% Vol 0.01 % Vol PM Continuous
STD- Standard NDIR bench for Biogas/Landfill applications
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
BM- Optimized NDIR bench for BIOMETHANE applications 
CH4% 0-100% ± 0.5% Vol 95-100 % 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
BMT- Low Range NDIR bench for CH4 and CO2 traces ( gas impurity) for BIOMETHANE application
CH4 ppm 0-30000 ppm ± 3% of rdg 1 ppm NDIR Continuous
CO2 ppm 0-30000 ppm ± 3% of rdg 1 ppm NDIR Continuous
H2S measurements
H2S 0-5000 ppm
0-250000 with Dilution**
± 5 ppm 1 ppm EC Continuous or  Sample
H2S 0-50 ppm
0-2500 ppm with Dilution**
± 5 ppm 1 ppm EC Continuous or Sample
H2S 0-200 ppm
0-10000 with Dilution**
± 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
** Dilution System Dilution of 50:1 factor using AIR- Dilution can be set to be always on or active on Threshold which is user defined.  It is possible to calibrate / adjust with test gas when dilution is switched on to eliminate any measuring errors caused by dilution
AutoCal Fully automated calibration function as standard to maintain CH4 and other Gas Accuracy.
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 case gas leak detection system
Analyser shut-off  in case of gas leak detection
Stainless Steel flow orifice restriction
Cabinet Marking  II 3G Ex nA IIA T1 GC
Certification Type ATEX
Certificate number EPS 16 ATEX 1 182 X
Dimension 700x600x210 (H x W x D) wall mounting ( bracket supplied)
Weight App: 40 KG
Case Material High Grade Stainelss Steel
IP Protection IP 65
Operating Temperature +5 to 45 °C ( -20 to 45 °C with optional heater)
Heater Optional Cabinet Heater 200 W  -ATEX
Mains Options 230 Vac / 47 -63 Hz / 90 W (115 Vac power supply on request)
Notes ∗ After Calibration and do not include calibration gas accuracy
** Due to continuous product improvement specifications might change with-out prior notice

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SWG100 BIOEX – Fixed Gas Analyser ATEX certified