Boreal Laser OPX vs. RPX Measurement Heads: What's the Difference?

Both the Open Path (OPX) and Remote Point (RPX) heads are accessories that turn a GasFinder3 Analyzer into a complete laser-based gas detector — the difference is where and how they measure. The OPX head creates an open-path detector for leak detection or ambient monitoring across an open span, while the RPX probe creates a fixed point detector for fast, localized measurement that resists poisoning and fouling. Neither head works on its own; each must be paired with a GasFinder3 Analyzer.

The shared foundation: TDLAS and the GasFinder3 Analyzer

Boreal Laser's instruments use Tunable Diode Laser Absorption Spectroscopy (TDLAS) to analyze, monitor, measure, and detect specific target gas molecules. The company positions this technology for toxic, combustible, hazardous, and greenhouse gases in industrial hazardous-area applications, and its products are used in 48 countries, with the company citing quantitative performance in difficult applications, fail-safe design, and maintenance-friendly operation as adoption drivers.

The measurement head is the field-side element; the GasFinder3 Analyzer is the processing unit. Choosing between OPX and RPX is therefore a question of measurement geometry and application, not of detection technology.

Open Path (OPX) Head

When combined with a GasFinder3 Analyzer, the OPX head forms a laser-based open-path gas detector used in industrial leak detection or ambient monitoring applications.

• What it measures: gas along an open line-of-sight path rather than at a single enclosed point — Boreal describes this as detecting gas "outside of the pipe."
• Best suited to: area-wide leak detection and ambient monitoring where you want coverage across a span, not just at one fitting or flange.
• Practical implication: because the measurement path is open, the reading reflects gas integrated along that path. This is the right choice when the question is "is there gas in this area?" rather than "is this specific point leaking?"

Boreal also promotes a GasFinder Line of Sight (LoS) product for laser-based, all-in-one open-path gas detection, which is worth reviewing if an integrated open-path package fits the project better than a head-plus-analyzer combination.

Remote Point (RPX) Probe

When combined with a GasFinder3 Analyzer, the RPX probe forms a laser-based fixed point gas detector for applications that require fast speed of response or immunity to poisoning/fouling.

• What it measures: gas at a defined point, using a remote probe arrangement.
• Best suited to: locations where response time matters and where conventional point sensors would be vulnerable to poisoning or fouling — the two conditions Boreal explicitly names for this probe.
• Practical implication: this is the choice when you need to watch a specific, high-consequence location and want the measurement to keep working in a dirty or contaminating environment.

Side-by-side comparison

How to choose

1. Define the measurement question. If you need to know whether gas is present across an area or along a fence line or process boundary, the OPX head matches that open-path use. If you need to know about one specific location, the RPX probe matches a point measurement.
2. Check the environment at the measurement site. Where poisoning or fouling would degrade a conventional point sensor, Boreal specifically positions the RPX probe for that condition. Where the concern is coverage of an open area, the OPX head is the stated fit.
3. Confirm the analyzer pairing. Both heads are described only in combination with GasFinder3 Analyzer products, so the analyzer is part of either configuration.
4. Verify the target gas. Boreal maintains a products-by-gas listing; confirm your target gas is detectable with laser-based detection before finalizing the head choice.
5. Engage the regional sales organization. Boreal states that its products are promoted, quoted, sold, commissioned, and supported by regionally focused technical sales organizations specializing in analytical and detection solutions, and it lists distributors on its site. Use these channels for configuration, quoting, and commissioning details — the public page does not publish pricing.

Common pitfalls

• Treating the heads as standalone detectors. The source describes each head only as part of a GasFinder3 system; plan for the analyzer in the same bill of materials.
• Assuming OPX gives a point reading. An open-path measurement integrates across the path, which is a different quantity from a point concentration.
• Overlooking the in-situ options. If the gas is inside a pipe rather than outside it, Boreal's Stack/Duct (SDX) and Insertable (IPX) probes are the relevant heads, not OPX or RPX.

For direct confirmation of compatibility, gas coverage, and commercial details, contact Boreal Laser or its regional distributor; the company lists sales and support at +1.780.488.5173.