SERVOTOUGH hazardous area

Change is in the air with the Laser 3 Plus Environmental for NOx reduction processes

A key part of our three-phase strategy for clean air, the Laser 3 Plus Environmental is our latest solution for accurate ammonia (NH3) measurements in DeNOx processes, and is designed to help you take control of your combustion emissions.

A fast-response measurement for ammonia slip

The SERVOTOUGH Laser 3 Plus Environmental is a revolution in Tunable Diode Laser (TDL) Absorption Spectroscopy analysis: a highly compact gas monitor for in-situ cross-stack applications, which delivers exceptional performance benefits for clean air processes.

Installed directly into process ducts, it is ideal for monitoring ammonia slip during NOx reduction processes such as Selective Catalytic Reduction (SCR) or Selective Non-Catalytic Reduction (SNCR), controlling the level of ammonia slip to between 2-3 parts per million

Delivering an average measurement of NH3 across the duct, it returns precise readings even during inconsistent flow conditions. With  auto-validation software available to ensure ongoing accuracy, the Laser 3 Plus Environmental provides industry-leading installation flexibility and cost and performance benefits.

Rhys Jenkins
IP&E Spectroscopic Product Manager

Change is in the air with revolutionary TDL gas analysis

Combining the latest advances in hardware with leading-edge software processing, the SERVOTOUGH Laser 3 Plus is a revolutionary step forward for TDL gas analysis in clean air strategies for industries around the world. Fast-response ammonia sensing is supported by advanced auto-validation software that ensures ongoing accuracy, making the analyzer ideal for NOx reduction processes. It provides unparalleled installation flexibility, along with significant cost and performance advantages that will benefit plant and refinery clean air strategies.

Low maintenance, low cost-of-ownership

The next-generation ethos of the Laser 3 Plus works hard to reduce costs at all stages. In addition to the immediate advantages of TDL technology – a non-depleting measurement which requires no sample conditioning system – the Laser 3 Plus compact design greatly reduces installation time, with small, light intuitive alignment for easy installation and maintenance. It has full ethernet communications for commissioning, diagnostics and trouble shooting.

High performance monitoring

The hardware advances of the Laser 3 Plus are matched by advanced Wavelength Signal Modulated Spectroscopy processing software, which eliminates drift over extended operational periods by automatically tracking on a sealed reference cuvette absorption line – line lock technology. This robust tracking mechanism ensures a highly reliable and accurate operation over long periods, with calibration frequencies extended beyond twelve months for many applications. The result is a sturdy, general purpose and hazardous area optimized design which ensures Laser 3 Plus can handle the most challenging of locations, including particulate-rich environments.

Looking to boost your clean air strategy? We can help

If you need a gas analysis system for your DeNOx application, emissions control and monitoring, or any other application, get in touch with our experts. We provide the process knowledge and engineering skills you need to see your project through to a successful conclusion.

Ready to buy? Here’s how it works

It’s easy to find the product you need for your application with Servomex


Get in touch to tell us what you need and the application you plan to use it for


Our expert team will help you select the right product package, ensuring you have the accessories and support to get the best performance from your analyzer


Your analyzer will be assembled in one of our state-of-the-art engineering centers and rapidly dispatched to your site

See the benefits for your clean air strategy

The compact Laser 3 Plus Environmental TDL analyzer is specifically optimized for the fast, accurate and responsive measurement of ammonia (NH3) in NOx reduction processes.

A reliable measurement

Servomex’s own line lock cuvette technology and auto-validation software ensure the analyzer continues to measure ammonia reliably.

Easy to use

The compact Laser 3 Plus Environmental is simple to install, with a user-friendly interface and range of digital communications options.

Hazardous area approvals

The Laser 3 Plus Environmental meets ATEX, IECEx and North American hazardous area approvals, and is IP66 and SIL 2 rated.

Unrivalled performance

  • Process temperatures up to 600°C *
  • Low detection limit
  • Negligable zero drift
  • Auto-validation capability
  • Calibration every 6-12 months

* Application and measurement dependent


  • Compact design
  • Performs in high particulate environments
  • Path lengths from 0.7m to 10m
  • Minimal cross interference
  • Diverse mounting: ideal for ducts, stacks and reactor installations

Easy to use

  • Simple to install and operate
  • Robust and reliable
  • Space saving
  • Digital communications
  • Modbus over Ethernet
  • User friendly interface and rapid disconnect for easy calibration

Low cost of ownership

  • Intuitive alignment for easy installation and maintenance
  • Non-depleting TDL technology
  • No moving parts, no consumables
  • No sample conditioning system – reduced maintenance costs
  • No hazardous area purge required

Benchmark compliance

  • ATEX, IECEx hazardous area approvals
  • North American hazardous area Class 1 Div 2

Gases sensed, measurements and technologies

The SERVOTOUGH Laser 3 Plus Environmental delivers exceptional TDL performance, with a fast response to measuring ammonia in DeNOx applications.

Gas Measurement
Ammonia (NH₃)ppm


Tunable Diode Laser


  • ATEX Cat 3 (Gases)
  • IECEx Zone 2 and Zone 21
  • North American Class 1 Division 2 and Zone 2 (Gas and Dust) pending
  • ATEX Cat 21 (Dust)
  • Safe Area / General Purpose
  • CE marked in compliance with ATEX, EMC, LVD and all other applicable directives

Schematics (select to expand)


131mm width (51/8”) 164mm high (61/2”) 302.4mm deep (119/10”)

110mm width (45/16”) 146mm high (53/4”) 247.6mm deep (93/4”) 


TRANSMITTER: <3.0 kg (6.6 lbs)

RECEIVER: <2.0 kg (4.4 lbs)

Get the detailed specifications

“For in-depth specifications you’ll want to download our technical datasheet which includes information on technology, performance, operating environment, sample conditions and compliance along with technical drawings and top-level benefits and applications.”

Rhys Jenkins
IP&E Spectroscopic Product Manager

Download your complete resource pack for the Laser 3 Plus Environmental

“Find out everything you need to know about this compact, fast-response TDL analyzer for clean air DeNOx strategies.  Our Laser 3 Plus Environmental resource pack contains the product brochure, operator manual, and other essential materials.”

Rhys Jenkins
IP&E Spectroscopic Product Manager

Manuals and brochures

For key information about the features, benefits and technical specifications of the Laser 3 Plus Environmental, download the operator manual and product brochure.

SERVOTOUGH Laser 3 Plus Product Configuration

SERVOTOUGH Laser 3 Plus Product Configuration

SERVOTOUGH Laser 3 Plus Certification Manual

SERVOTOUGH Laser 3 Plus Certification Manual

SERVOTOUGH Laser 3 Plus Operator Manual

SERVOTOUGH Laser 3 Plus Operator Manual

Laser 3 Plus Ammonia Spares

Laser 3 Plus Ammonia Spares

See for yourself

Our videos give you the chance to watch our products in action and hear from our experts. You can also see our analyzers unboxed, and find out more about our solutions for key applications

Laser Application in Ammonia Slip

Doscover how the SERVOTOUGH Laser 3 Plus provides a complete gas analysis solution for ammonia slip applications.

Typical applications

A key part of our strategy for clean air solutions, the Laser 3 Plus Environmental is a TDL analyzer specifically optimized to measure NH3 in ammonia slip DeNOx applications.

Process heaters and furnaces

A choice of technologies to fit your application

Learn more

Coal-fired thermal power

Our total analytical solution delivers benefits in cost, process efficiency, safety and emissions across the process

Learn more

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