How Boreal Laser's Open Path Gas Detection Works

Boreal Laser's open path gas detection works by pairing a GasFinder3 Analyzer with an Open Path (OPX) Measurement Head to form a laser-based detector that measures target gas concentrations across an open beam path rather than at a single enclosed point. The measurement principle is Tunable Diode Laser Absorption Spectroscopy (TDLAS): the analyzer tunes a diode laser across a narrow absorption feature of the target gas and quantifies concentration from the light absorbed along the path. This configuration is intended for industrial leak detection and ambient monitoring, and the company positions it for immediate, unambiguous detection of toxic and combustible gases.

The measurement principle: TDLAS

TDLAS exploits the fact that each gas molecule absorbs light at specific, narrow wavelengths. Boreal Laser's instruments tune a diode laser across one of these absorption lines and compare the transmitted light against the expected signal. Because the absorption feature is unique to the target molecule, the measurement is selective for that gas, and the depth of the absorption gives a quantitative concentration.

Boreal Laser describes its core product as an "Enhanced Sensing Element" that measures gas concentrations in industrial hazardous-area applications, and states that the TDLAS principle is suited to detecting and monitoring toxic, combustible, hazardous, and greenhouse gases. The company also emphasizes three design priorities for these instruments: quantitative performance in difficult applications, fail-safe design, and maintenance-friendly operation.

How the hardware fits together

The open path detector is not a single standalone unit. It is built from two elements:

The same GasFinder3 Analyzer line also supports other measurement heads for different geometries, which is useful for understanding where open path fits:

• Open Path (OPX) Head — open-path detector for industrial leak detection or ambient monitoring.
• Remote Point (RPX) Probe — fixed-point measurement for applications needing fast response or immunity to poisoning/fouling.
• Stack/Duct (SDX) Probe — direct, non-contact measurement inside a stack or duct for quantitative or feedback control.
• Insertable (IPX) Probe — in-situ measurement within a process line.

In short, the OPX head answers "what is in the air outside the pipe," while the SDX and IPX heads answer "what is inside the pipe."

What "open path" means in practice

A conventional point detector waits for gas to reach a sensor housed in an enclosure. An open path system instead sends the laser across an open span — for example, across a process area, along a pipe rack, or around a loading zone — and measures absorption over that entire line. This has two practical consequences:

1. The measurement is integrated over the path. The reading reflects gas present anywhere along the beam, which suits area monitoring and leak detection where the release location is not fixed in advance.
2. There is no sampling system to foul. Because the beam travels through open air, the measurement is non-contact and does not depend on gas being drawn into a sensor.

The trade-off is that an open path measurement is a path-average, not a point concentration, and the beam must have a clear line of sight between launch and receive points.

Where it is used

Boreal Laser lists two primary applications for the OPX configuration: industrial leak detection and ambient monitoring. The broader product family covers fixed leak detection, in-situ and extractive analysis, transportable gas detection, and mobile gas detection. The company reports adoption in 48 countries, with products sold, commissioned, and supported through regional technical sales organizations — a relevant detail if you need local commissioning support rather than direct factory purchase.

Deciding whether open path fits your site

Open path TDLAS is a reasonable candidate when:

• You need to monitor a defined area or span rather than a single enclosed location.
• The target gas is one of the toxic, combustible, hazardous, or greenhouse gases the platform supports (Boreal Laser maintains a detectable-gases list on its site).
• You want a non-contact measurement without extractive sampling hardware in the beam path.
• You can provide a stable line of sight and mounting for the OPX head and analyzer.

It is a weaker fit when you need a true point concentration at one specific location, when the beam path cannot be kept clear, or when very fast point response is the priority — in which case the RPX remote point probe is the more direct comparison within the same analyzer family.

For gas-specific detectability, application matching, and regional sales or support contacts, the company directs users to its products-by-gas and products-by-application pages and to its distributor list.