Laser Gas Detection Module NH₃ (TDLS)


Rack 3U monitor using the TDL extractive technology to measure online the NH3 pre and/or post catalyst: SCR (Selective Catalytic Reduction) or SNCR (Selective Non-Catalytic Reduction)

ENVEA offers this rackable and small footprint NH3 measurement system (3U rack) integrated in its turnkey analysis benches for continuous engine gas measurements.

Its measuring principle is based on gas detection by tunable diode laser spectrometry (TDLS) which offers many advantages and an exceptional value for the customer.

  • Made for easy integration in our turnkey EGAS analysis cabinets
  • Optical, contact-less measurement
  • Accurate NH3 monitoring using TDL spectroscopy
  • High selectivity
  • Fast response time
  • Self-contained
  • Continuous sensor status monitoring
  • No maintenance required, no need for re-calibration
  • Low cost-of-ownership
  • Digital and analog data interfaces
  • Hot-gas measurement up to 190°C
In DeNOx systems using urea injection with ammonia (NH3) as a reducing agent, the flow rate and control of NH3 must be continuously adjusted and controlled to prevent excess NH3 emissions (slip), thus reducing environmental impact and cost of reagents. Therefore, to optimize this process, it is necessary to use a continuous emissions analysis system for the online monitoring of NH3.

  • Automotive Test Systems
  • Motor Exhaust Gas Analysis
  • Catalyst testing in automobile, aeronautics and all kind of engines and components
  • Process control & combustion processes
Technical specifications
Gas NH3
Principle of detection Tunable Diode Laser Spectrometry (TDLS)
Ranges 0-100 / 0-20 ppm
Precision 2σ 1.8 ppm @ 1 s
0.8 ppm @ 10 s
Response time < 2 sec (T90) (at gas flow rate of 3 L/min)
Zero drift below accuracy / 24 h (<±2.0 % full scale reading depending on  stability (temperature & pressure)
Span drift below accuracy / 24 h (<±2.0 % full scale reading depending on  stability (temperature & pressure)
Cell temperature range 190°C
Operating temperature +15 to +50°C
Communication RS 232
Dimensions Rack 19″ – 3U
Turnkey Engine Exhausts NH3 cabinet
LGD 2M Turnkey design

Compact NH3 bay, 13U, 79Kg.

LGD 2M Turnkey design

NH3 bay, 22U, 171Kg.

Example of custom integration.
For other configurations, please, contact us
Approvals & certifications
European Conformity: Low voltage
EMC compatibility
CE 2006/95/EG
Safety of laboratory products EN/IEC 61010
Safety of laser products EN/IEC 60825-1
EMC EN/IEC 61326-1
Shock EN60068-2-27
Vibration EN60068-2-6
Electronics conformity RoHS / WEEE

All our EGAS (Engine Gas) range of products is fully compliant to the worldwide vehicle Emission Standards, including CFR 40 -1065, Diesel 2007/2010, Euro V & Euro VI, EEM (Engine Emission Monitoring)