AtLAS-900 is a laser gas analyser for industrial on line applications, able to measure a great number of gas but optimized for Oxygen measurement (inerting control) in centrifuges and reactors in chemical and pharmaceutical industry, as well as in biogas and landfill gas.

The sample bypass tube can be in Stainless Steel or Teflon-Coated in case of sample gas with aggressive substances.

The TDLAS technology provide an incredibly fast response time, small drift and measure virtually free from interference’s of other gases.

Available for safe area or for hazardous area classified Zone 1 / Zone 21 (ATEX certified).


Measurable Gas

Oxygen [O2]

Water [H2O]

Hydrogen Fluoride [HF]

Acetylene [C2H2]

Carbon Monoxide [CO]

Hydrogen Sulfide [H2S]

Ammonia [NH3]

Ethylene [C2H4]

Carbon Dioxide [CO2]

Hydrogen Chloride [HCl]

Methane [CH4]

Combined Versions

Carbon Monoxide + Carbon Dioxide [CO+CO2]

Ammonia + Water [NH3 + H2O]

Hydrogen Chloride + Water [HCL + H2O]

Hydrogen Fluoride + Water [HF + H2O]


Main Features

High Performance

  • Adopting wavelength-modulation-spectroscopy allows better signal/noise ratio and anti-interference capability of dust and background gas
  • Single line spectrum technology, free from interference of background gas
  • No cross sensitivity due to the presence of solvents
  • Extremely high stability and repeatability
  • Almost instantaneous response time


Easy to Use

  • Modular design makes field maintenance operations very easy
  • Simple to clean in case dirty deposits on the optical parts


Low Costs of Ownership

  • It requires a simple sampling system
  • No depleting or consumable parts that need to be periodically replaced or refilled



  • I/O interface, self-diagnosis and alarm s
  • Local OLED display with magnetic keys, operated by magnetic pen without opening the housing


European Compliance

  • Low Voltage Directive 2014/35/EU
  • EMC Directive 2014/30/EU


ATEX certification for Zone 1 / Zone 21 with protection mode:

II 2 G D      Ex db op is IIC T6 Gb Ex

Ex tb op is IIIC T80°C Db

Ta = -20°C to +60°C

ATEX Certificate Number CML 18 ATEX 1400X



SIL 2 [ pending ]



Performance Specification
Measuring Principle TDLAS (Tunable Diode Laser Absorption Spectroscopy)
Light Source Semiconductor Laser
Accuracy ≤ ±1% FS
Linearity Error ≤ ±1% FS
Repeatability ≤ ±1% FS
Span Drift ≤ ±1% FS / 6 months
Zero Drift ≤ ±1% FS / 6 months
Maintenance Cycle ≤ 2 times / year (clean optical window)
Calibration Cycle ≤ 2 times / year
Enclosure Rating IP66
Response Time ≤ 1 sec. at T90
Optical Path Minimum 350 mm for O2
Analog Output 2 x 4-20 mA isolated (max. load 750 Ω)
Analog Input 2 x 4-20 mA isolated (for temperature and pressure compensation, if necessary)
Digital Output RS485 / RS232
Relay Output 3 x (24V, 1A)
Operative Specification
Sample Flow Rate 2000 ÷ 5000 cc/min.
Pressure Max. 3 bar abs.
Power Supply 24 Vdc or 100…240 Vac, ≤ 20W
Ambient Temperature -20°C….+60°C
Ambient Humidity ≤ 90% non-condensing
Installation Extractive
Pneumatic Connections 2 x fittings for tube O.D. 8 mm (In / Out)
Wiring Connections 1 x armored cable gland for cable 6.5÷10.5 mm.
3 x threaded hole M20 x 1.5 (with plug)
1 x threaded hole M25 x 1.5 (with plug)
Physical Specification
Dimensions Refer to dimensional layout
Weight 26 Kg. total
Wet Parts Materials Analyzer: K9/JGS2 Quartz, Teflon
Analysis tube: SS 304 or SS304 Teflon-Coated


  • Inerting Control
  • Centrifuges
  • Reactors
  • Chemical and Pharmaceutical Industry
  • Biogas & Landfill Gas
  • Solvents Recovery
  • Fertilizers

Sampling System


The AtLAS-900, configured as extractive, needs an external sampling system able to deliver the sample gas to the analyzer. The sample gas only contacts Quartz and Teflon (or AISI) and this makes the analyzer parts totally free from most of the aggressive substances. Again, there are not moving parts and the analyzer can even withstand with the direct ingress of liquid and it can be sterilized.

The extremely simplified and resilient design allows to reduce to the minimum the sampling systems components upstream the analyzer.

Measuring Principle


TDLAS (Tunable Diode Laser Absorption Spectroscopy) mainly uses the character that Tunable laser’s narrow band and wavelength change with the current. So, by precisely modulating the current of tunable laser, it can scan a certain absorption peak of detected gas (no absorption of background gas).

And after obtaining the second harmonics absorbed by detected gas, it finally works out the concentration of detected gas by using this second harmonics and line-width.

The TDLAS technology has been developed into a kind of high sensitivity, high resolution, fast response time and high selectivity of gas detection technology, widely used in industrial process monitoring control.

By using a tunable semiconductor laser, AtLAS-900 scans the specific absorption line of the measured gas (no background gas) to get the second harmonic of the gas. Through processing and analyzing the second harmonic and the broadening information of the gas, the concentration of the gas is obtained.