TDLAS & QF Analyzers

TDLAS & QF Analyzers

TDLAS & QF analyzers are optical gas analysis instruments designed for fast, selective, online measurement of key components in process gas streams. Tunable diode laser absorption spectroscopy (TDLAS) uses laser absorption to quantify target analytes such as H₂O, H₂S, and CO₂, while quenched fluorescence (QF) technology is applied to measure oxygen from trace levels to percent concentrations. These techniques are deployed where conventional methods struggle with response time, sample integrity, or maintenance burden.

TDLAS works by tuning a laser across an absorption feature of the target molecule and measuring the attenuation through the gas path, yielding high selectivity and rapid response. QF oxygen analyzers excite oxygen molecules and measure fluorescence quenching behavior to determine concentration across wide ranges. Both approaches are well-suited to continuous, online measurement and can be implemented in configurations that minimize sample handling and reduce analyzer drift associated with complex conditioning systems.

The value proposition is improved control with lower operating cost. Reliable, real-time gas concentration data supports tighter quality control and more stable process control, while reducing operational costs and maximizing process uptime. Because the measurement is inherently optical and selective, the instrumentation can deliver actionable data with fewer consumables and less frequent intervention than many wet-chemistry or indirect methods.

Typical applications include moisture and acid-gas monitoring in natural gas and refining streams, H₂S control for safety and product specification, CO₂ measurement for process efficiency, and oxygen measurement for inerting, purge validation, oxidation control, and combustion support. In packaged units, these analyzers are used where fast response is required to protect equipment and maintain product quality during transients such as startups, grade changes, or upset conditions.

Implementation emphasizes selecting the right measurement configuration for the process - defining required range, response time, and installation location to ensure representative measurement. Optical path integrity, window management, and verification routines are planned so that performance is sustained over long operating intervals. When integrated into control and safety logic, TDLAS and QF analyzers provide high-confidence measurements that enable both performance optimization and risk reduction.

Instrumentation and Controls., an exclusive authorized representative of sales and service for Endress+Hauser.