Stack/Duct (SDX) Probe Assembly

For the GasFinder3-DC (DUAL CHANNEL)


The GasFinder3-DC and the associated Measurement Heads are a field deployable Open-Path Tunable Diode Laser (OP-TDL) based gas analyzer system that is primarily used for:

  • Leak Detection – provides immediate and unambiguous detection of fugitive gas releases in industrial safety applications
  • Ambient Monitoring – Continuously monitors gas concentrations over open area and/or point sources for environmental monitoring applications

This technology is also most commonly referred to as Open Path Gas Detection (OPGD) or Line of Sight (LOS).

This particular technology is ideal for detecting or monitoring for a number of different Toxic, Combustible, Hazardous, or Greenhouse Gases.

Core System Components

GasFinder3-DC: is the analyzer or also known as a CCU or Controller. The GasFinder3-DC houses the laser and electronics.

Measurement Head(s): attachment used to form the Active Measurement Path and provides the direct sample for the GasFinder3-DC to analyze. There are three core Measurement Heads available for the GasFinder3-DC – Open Path (OPX) Head, Remote Point (RPX) Probe, and the Stack/Duct (SDX) Probe.

Accessories: additional components used to provide additional functionality or increase ease of use for the end-user.

Use Applications:

Hydrogen Fluoride (HF) Monitoring in Primary Aluminium:

Gas Treatment Centre – Inlet Monitoring:

The HF concentration in the inlet duct of the GTC is a leading indicator of pot performance (pot gas recovery and top heat balance). Provides feedforward measurements to control and react to higher inlet HF concentrations before stack emissions increase to unacceptable levels. These measurements provide knowledge of whether high stack emissions are due to issues within the pot room , the GTC, or both. The Inlet Monitoring Measurements provide fast indication for pot balancing activities.

Gas Treatment Centre – Bag House Compartment Monitoring:

Increased production or tightening emission regulations may require increased HF scrubbing capacity. Rather than undergoing a large capital expense to design and build a wet-scrubbing system it may make better economic sense to optimize dry-scrubbing performance. HF concentrations in the stack are often the result of one bad filter compartment. By using a multi-channel OP-TDL analyzer to continuously measure HF in each bag House compartment a bad filter can be quickly identified and isolated resulting in minimal impact on stack HF emissions.

Gas Treatment Centre – Stack Monitoring: 

The probe is an engineered solution for our series of GasFinder analyzers to remotely monitor the path average concentration inside of the stack. Unlike some stack monitoring vendors, Boreal Laser does not mount the analyzers electronics directly on the stack as the high ambient temperatures and stack temperatures reduces the accuracy and significantly reduces the lifespan of the analyzer. Boreal laser has a patented internal reference cell that does not require routine intervention or zero/span gas to eliminate measurement drift as this is done automatically once a minute.

Ammonia (NH3) and Hydrogen Chloride (HCl) in Waste to Energy:

Robust, accurate, and fast direct detection of Ammonia (NH3) and Hydrogen Chloride (HCl) for Sulfur Catalytic Reduction (SCR) in Waste to Energy Applications.

 Building a GasFinder3-DC Assembly:

The table below is your way to build and configure your very down GasFinder3-DC Assembly.

 GasFinder3-DC Models:

While all three (3) models have the same performance specifications, each of the models differ by features and functionality to help match the requirements of the end-user.


 Differences Between Models:

Below is quick breakdown of the differences between each of the GasFinder3-DC models.

Additional Options for GasFinder3-DC:

The following highlight the additional options that enable a customized solution to meet your applications needs.

Target Gas:

The lasers used emit light in the Near Infrared and can detect/monitor the following gases:

 Building a Measurement Head Assembly:

The table below is how to build the Measurement Head Assembly that is best suited to your application.


 Connecting the Measurement Head to the GasFinder3-DC:

Below are the following options available to mount the Measurement Assembly of your choice just where you need it.

Measurement Head Options:

The following are the most popular Measurement Heads available for the GasFinder3-DC.



Below are the most popular accessories selected.


Applications Engineering Review:

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