TDLAS & QF Analyzers

TDLAS & QF Analyzers

TDLAS (tunable diode laser absorption spectroscopy) and QF (quenched fluorescence) analyzers are optical gas analysis technologies used for high-performance, continuous concentration measurement in gas streams. TDLAS applies laser absorption to quantify target analytes such as H₂O, H₂S, and CO₂, while QF is used for oxygen measurement from trace levels to percent ranges. These approaches emphasize fast response and long-term stability in demanding gas measurement duties.

The benefit is measurement reliability with reduced operational burden. Non-contact optical measurement concepts can protect critical analyzer components from direct interaction with the sample, improving robustness and reducing routine maintenance and recalibration needs. For oxygen service in natural gas, QF methods are specifically positioned to be resistant to common contaminants and sour gas constituents that can compromise traditional sensor technologies.

These analyzers support both quality control and process control by providing near real-time measurement where delays can translate into off-spec product, corrosion risk, or equipment damage. Water content measurement supports dehydration performance and hydrate prevention strategies; H₂S measurement supports safety and gas quality objectives; CO₂ measurement supports processing and contractual requirements; and oxygen measurement supports detection of air ingress and protection of systems sensitive to oxidation.

Typical applications include natural gas pipelines, processing trains, and LNG facilities, as well as refineries and petrochemical operations where fast composition feedback supports control and safeguarding. Biogas analysis and other gas-stream monitoring tasks are also common where optical selectivity and stability provide advantages over more maintenance-intensive approaches.

Selection considerations include target component list and measurement range, required response time, installation environment (field mount, analyzer shelter, hazardous areas), and integration philosophy (analog outputs, digital communications, and diagnostics). A well-designed deployment treats the analyzer as part of a measurement system - addressing sample handling as needed, validation practices, and maintenance access - so the optical advantage translates into sustained performance over the full lifecycle.

Miller Mechanical Specialties, an exclusive authorized representative of sales and service for Endress+Hauser.