Open Path (OPX) Head Assembly

For the GasFinder3-DC (Dual Channel)


The Open Path (OPX) Head Assembly consists of Open Path (OPX) Measurement Head, Retro-Reflector, and Cable Kit. When the Open Path (OPX) Head Assembly is combined with the GasFinder3-DC, it creates an Open-Path Gas Detector that uses laser light to detect specific target gas molecules.

Open Path Laser Gas Detectors are used primarily for these applications:

  • Leak Detection – provides immediate and unambiguous detection of fugitive gas releases in industrial safety applications.
  • Ambient Monitoring – Continuously monitor gas concentrations accurately and reliably over open area and/or point sources for environmental monitoring applications.
Schematic of the Open Path (OPX) Head Assembly with the GasFinder3-DC:

This technology is also most commonly referred to as Open Path Gas Detection (OPGD) or Line of Sight (LOS). Boreal Laser has been commercially selling this technology since the 90’s and the original installations are still operational today. The products long lifespan is a testament to Boreal Laser’s focus to quality.

This particular technology is ideal for detecting or monitoring for a number of different Toxic, Combustible, Hazardous, or Greenhouse Gases. The most popular gases include: Hydrogen Sulfide/Sulphide (H2S), Ammonia (NH3), Hydrogen Fluoride (HF), Methane (CH4), Carbon Monoxide (CO), and Carbon Dioxide (CO2).

Boreal Laser products are widely adopted in 47 countries in industrial applications primarily for its large area coverage, fast speed of response, and maintenance friendly operation. With Open Path Gas Detectors (OPGD), you’re more likely to detect the presence of a leak than compared to slow to respond traditional point detectors.

Core System Components

There are three categories of components: Analyzers, Measurement Heads, and Accessories.

GasFinder3-DC Assembly: Is the analyzer or also known as a CCU or Controller. The GasFinder3-DC houses the laser and electronics. This particular product can have either one (1) or two (2) Measurement Heads connected at the same time. The GasFinder3-DC can be installed in a Class 1 Div/Zone 2 classified areas. The GasFinder3-DC is SIL2 Suitable.

Open Path (OPX) Head Assembly: The OPX Head and Retro-Reflector are the components used to form the Active Measurement Path. The OPX Head can be installed in Class 1 Div/Zone 1 classified areas.

Accessories: There are accessories that make installation, alignment, commissioning, and troubleshooting process easier. Examples of these accessories are shown below.

Use Applications:

Hydrogen Fluoride (HF) Monitoring in Alkylation Unit:

Early warning for the release of the toxic Hydrogen Fluoride is critical. The wide area coverage, one second response time, and very low detection limits make Open Path Laser Gas Detection ideal. Boreal Laser is the trusted gold standard by both HF Alky industry associations, corporate wide installations, and the technical solution for individual facilities needing to meet the requirements of Quantitative Risk Assessments.

Methane (CH4) Monitoring on Tank Farm:

The Open Path Laser Gas Detection is more than capable of monitoring atmospheric concentrations of methane. Boreal Laser is known as the gold standard for ambient methane monitoring not only by industry but with academia and researchers as well. This technology is perfect for remote applications as there is no requirement for routine calibration or intervention.

Carbon Dioxide (CO2) Monitoring on Heat Exchanger:

Boreal Laser’s GasFinder3-DC and Open Path (OPX) Heads are often used in applications where traditional technology cannot survive the harsh environmental and/or process conditions. Since our Open Path Gas Detector use laser light as its measurement sensor it is well suited to the troublesome applications in your facility.

Why is the GasFinder3-DC Different:

The GasFinder3-DC (Dual Channel) can have two Measurement Head Assemblies connected to form two independent Active Measurement Paths.

Boreal Laser has a patented internal reference cell that does not require routine intervention or zero/span gas to eliminate drift as this is done automatically and once a minute.

Measure only the target gas and all of the target gas. Boreal analyzers do not suffer from cross interference and are not affected by humidity.


Build a tailor made solution

Building a GasFinder3-DC Assembly:

The GasFinder3-DC has been designed to be the choice of Technicians, Engineers, and Operators. The difference with Boreal Laser and the GasFinder3-DC is the end-user can build the analyzer configuration ideally suited for their application.

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

 Model Selection:

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. For more specific information about gas specification you can reference:

 Building a Measurement Head Assembly:

No two application are the same, so why have a one size fits all solution? You have the ability to pick just the right cable length to connect the Open Path (OPX) Head to the GasFinder3-DC and you can configure your Retro-Reflector that is perfect for your application.

The table below is how to build the Measurement Head Assembly that is best suited to your application. The blue bracketed letters and numbers allow you to build your own part #.


 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.

Open Path (OPX) Head Components:

The following are the components within the Open Path (OPX) Head Assembly.

Retro-Reflectors for Open Path (OPX) Head Assemblies:

There are number of options available to customize the optimal Retro-Reflector for your application. You have the option of Retro-Enclosure material, Retro-Array size, voltage requirements for the Retro-Heater.


Below are the most popular accessories selected for the Open Path (OPX) Head Assembly and GasFinder3-DC.


Application Review

Selecting the best tool for the job

The more information we have the about your application the easier it is to provide you with the exact equipment configuration required. Either a Boreal Laser Representative or one of our many Distributors will work with you to ensure that this technology and product configuration is ideal for you application.


Need More Information?

Let us help.

The following email addresses are the ideal contacts with Boreal Laser or with one of our Authorized Distributors.

Technical Product Information:
Request Quotation:
Authorized Distributors: Click Here


Looking for documents?

Look no further.

The documents below are to help you through to first interaction through to final commissioning.