(SO2 + HCL + NO + H2O) Analyzer

Cross Duct Multi Gauge

GasEye Cross Duct MG

in-situ SO2 + HCL + NO + H2O analyzer

GasEye SO2/HCL/NO/H2O is a high performance in-situ sulfur dioxide, hydrogen chloride, nitric oxide and water vapor analyzer. Suitable for safety applications and process control. 24/7 continuous operation. No sample preparation. No zero drift. No field calibration. Low cost of ownership.


  • SO2 ranges: 0 – 5000 ppmv
  • HCL ranges: 0 – 10 ppmv to 0 – 1000 ppmv
  • NO ranges: 0 – 10 ppmv to 0 – 5000 ppmv
  • H2O ranges: 0 – 30 vol%
  • process temperature: 0 – 550°C
  • Real time sensing: response time below 0.2 second
  • High selectivity: automatic compensation for interference effect from other constituents in the gas sample
  • High sensitivity:
  • In-situ monitoring: direct in the process, no sample preparation
  • Maintenance free: equipped with a self-calibrating feature, no field calibration necessary
  • Robustness: IP66 enclosure, suitable for outdoor and indoor installations and harsh environments
  • Insensitive to dust and smoke in the measured process: up to 50 g/m3
  • ATEX version available

Example Applications

  • Process control
  • Emission monitoring

Example Industries

  • Power industry
  • Chemical industry

Application type

Analytical performance
Concentration measurement range SO2/HCL/NO/H2O: 0 – 5000 ppmv / 0 – 1000 ppmv / 0 – 5000 ppmv / 0 – 30 vol%
Detection limit (LOD) SO2/HCL/NO/H2O: 2 ppmv*m / 0.3 ppmv*m / 0.2 ppmv*m / 0.05 vol%*m
Precision: LOD or 1% of the measured value, whichever is larger
Accuracy: LOD or 2% of the measured value, whichever is larger
Process dust load: up to 50 g/Nm3 depending on the process
Calibration: certified span gas
Zero drift and span drift: negligible
Measurement conditions
Process gas temperature: 0ºC to 550ºC
Process gas pressure: 0.7 – 2.0 barA
Maximum path length: up to 25 meter
Dynamic performance
Warm-up time: approx. 5 minutes
Minimum response time (T90): 200 milliseconds
Climatic conditions
Ambient temperature: -30ºC to +55ºC
Ambient pressure: 800 – 1200 hPa
Ambient humidity: RH < 99%, non-condensing
Process Purging (if necessary)
Purging gas: instrument air or N2
Process purge flow rates: 5 – 50 l/min
Sensor purge flow rates: 0.2 – 7 l/min

Technical specification

Outputs: configurable 4 x analog output, 4 – 20 mA (for example: CO concentration, O2 concentration, process transmission, 1 x process temperature (optional)), easy user selection via DIP switch between active/passive mode
8 x digital output (NAMUR)
Inputs: configurable 4 x analog input, 4 – 20 mA (for example: process temperature, pressure), easy user selection via DIP switch between active/passive mode
1 x RTD (PT100/PT1000) - easy user selection via DIP switch between PT100/PT1000 and 2-/3-/4-wires
8 x digital input
Local User Interface: Human Machine Interface (HMI) - LCD backlight display located on the transmitter housing lid
Ethernet port:
a) WebServer – system configuration and data acquisition via web browser,
b) Windows based program – GasEye logger for real-time data acquisition,
c) remote service and diagnostics
Optional: Modbus (TCP/IP), Modbus RTU, Profinet, Profibus
Electrical Characteristics
Power input: 24 VDC nominal (19 – 30 VDC)
Power consumption: < 25 VA (< 35 VA if ATEX)
Additional build-in features
Automatic gain control (AGC): AGC ensures correct gas measurement even at high dust loads resulting in loss of optical transmission down to 0.5%. AGC operates fully automatic with no need for manual adjustment of the signal gain under any process conditions.
Self-calibration features: Internal reference gas compartment is used for closed loop control of the zero and span drift
Download a file:
GasEYE system elements: preview | download
Active analog input: preview | download
Active analog output: preview | download
Passive analog input: preview | download
Passive analog output: preview | download
Isolated Digital Input: preview | download
Isolated Digital Output: preview | download
Power Supply: preview | download
RemoteRX: preview | download
PT100/PT1000 2-wire: preview | download
PT100/PT1000 3-wire: preview | download
PT100/PT1000 4-wire: preview | download
Dimensions: width x height: 330 mm x 230 mm,
length: 350 mm
Weight: 15 kg
Equipment: 2 x laser sockets,
purging fittings
Dimensions: width x height: 160 mm x 160 mm,
length: 330 mm
Weight: 13 kg
Equipment: 1 cable gland,
purging fittings
Central Unit
Dimensions: width x height: 330 mm x 230 mm,
length: 110 mm
Weight: 5 kg
Equipment: display with status indicators,
6 cable glands, Ethernet socket,
purging fittings
Housings: RAL 5010 coated aluminum, (optional RAL 7040)
Process interface: stainless steel 316 with quartz window, DN50 PN16 (EN 1092-1), DN65 PN6 with easy to clean window, optional other standards (ANSI, JIS)
Purging tubes: inside diameter: 38 mm, length: 400mm (optional other dimensions), stainless steel 316 (optional PTFE coating)
Process gaskets: reinforced graphite
Download a file:
GasEYE Cross Duct units construction elements: preview | download
GasEYE Cross Duct instrument assembly: preview | download
GasEYE Cross Duct cross-section: preview | download


RoHS Directive 2011/65/EU
Low Voltage Directive (LVD) 2014/35/EU PN-EN 60825-1:2014-11 – Safety of laser products – Part 1: Equipment classification and requirements
PN-EN 61010-1:2011 – Safety requirements for electrical equipment for measurement, control and laboratory use – Part 1: General requirements
Electromagnetic Compatibility Directive (EMC) 2014/30/UE Emission:
EN 55016-2-1:2014+A1:2017 – Measurements of conducted disturbances emission
EN 55016-2-3:2017+A1:2019 – Measurements of radiated disturbances emission
EN 61000-4-2:2009 – Electrostatic discharge immunity
EN 61000-4-3:2006 + A1:2008 + A2:2010 – Radiated, electromagnetic field immunity
EN 61000-4-4:2012 – Electrical fast transient / burst immunity
EN 61000-4-5:2014 + A1:2017 – Surge immunity
EN 61000-4-6:2014 – Immunity to conducted disturbances
EN 61000-4-29:2000 – Immunity to voltage dips, short interruptions and voltage variations
ATEX Directive 2014/34/EU EN IEC 60079-0:2018 - Explosive atmospheres - Part 0: Equipment - General requirements
EN 60079-2:2014 - Explosive atmospheres - Part 2: Equipment protection by pressurized enclosure "p"
EN 60079-11:2012 - Explosive atmospheres - Part 11: Equipment protection by intrinsic safety "i"
EN 60079-26:2015 - Explosive atmospheres - Part 26: Equipment with Equipment Protection Level (EPL) Ga
EN 60079-28:2015 - Explosive atmospheres - Part 28: Protection of equipment and transmission systems using optical radiation
Explosion protection (standard version):

  • ATEX II 3G [Ex op is IIC T6 Gc]
  • ATEX II 3D [Ex op is IIIC T85°C Dc]
Explosion protection - ATEX Zone 1/21 (optional version):
GasEye Cross Duct Ex1:

  • II 1/2G Ex pxb op is IIC T6 Ga/Gb
  • II 1/2D Ex pxb op is IIIC T85°C Da/Db

GasEye Cross Duct Ex1 IS:

  • II 1/2G Ex pxb ia op is IIC T6 Ga/Gb
  • II 1/2D Ex pxb ia op is IIIC T85°C Da/Db

GasEye Cross Duct Ex1 ET and GasEye Cross Duct Ex1 ET IS:

  • II 1/2G Ex db eb h ia ib op is pxb q IIC T4 Ga/Gb
  • II 1/2G Ex h ia ib op is pxb q tb IIIC T135°C Da/Db

Certificate No. KDB 20ATEX0003X EN
Certificate No. KDB 20ATEX0003X PL

Explosion protection - IECEx Zone 2/22 (optional version):

  • op is pzc IIC T6 Gc
  • op is pzc IIIB T85°C Dc

Certificate No. IECEx KDB 19.0004X

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