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precisive tfs tunable filter spectrometer
Optical Gas Analyzer, Tunable Filter Spectroscopy, Natural Gas Pipelines


  • Measurement Technique
    Tunable Filter Spectroscopy
  • Measurement Channels
    CH4, C2H6, C3H8, i-C4H10, n-C4H10, C5H12, CO2, BTU Calorific/heating value, Wobbe index
  • Measurement Ranges
    Methane: 50 - 100% (C1)
    Ethane: 0 - 20% (C2)
    Propane: 0 - 10% (C3)
    iso-Butane: 0 - 5% (iC4)
    n-Butane: 0 - 5% (nC4)
    Pentanes (total): 0 - 2% (C5 lumped)
    n-Hexane: 0 - 2% (nC6)
    Carbon Dioxide: 0 - 20% (CO2)
    Calculated balance (N2, O2, H2) or analog inputs available for H2 and/or O2
    Calorific Value (CV) and Wobbe Index (WI) per ISO 6976:1995
  • Repeatability
    Hydrocarbon channels: ± 0.05% (absolute)
    CV & WI computation: ± 0.05% (relative of reading) or ± 0.01 MJ/m3 (greater of)
  • Zero Drift
    Not to exceed 0.2% per month on each hydrocarbon channel Maximum of 0.5% throughout life of bulb (~ 18 months) if not re-zeroed
  • Sample Pressure
    0.1 - 5 psig
  • Flow Rate
    0.1 - 2 L/min
  • Update rate
    5 seconds (default), software selectable from 1 - 120 seconds
  • Certifications
    CSA Class 1Div2, Groups A/B/C/D,T4. ATEx Zone 2, Ex nAnCIICT4Gc


Precisive TFS™ Light Absorption Spectroscopy Schematic

Simplified schematic of light absorption spectroscopy

The Precisive TFS™ (Tunable Filter Spectrometer) sensor platform consists of a light source, a sample cell (for gases, liquids or solids), a wavelength separating element (spectrometer) and a photo-detector. The wavelength separating element "slices" the wavelength components of the broadband light source which then interacts with the sample molecules. Some of the wavelength components are absorbed and some are transmitted through without any absorption.

Advanced Spectral Decomposition Algorithm

Light absorption spectroscopy with advanced spectral decomposition algorithm

Precisive TFS™ Tunable Filter Spectrometers use an advanced spectral decomposition algorithm. The resulting spectrum is called absorption spectrum, which acts as "fingerprints" which are used to identify the sample components and/or quantify the composition of the sample.

Precisive® 5-242B Natural Gas Pipeline Analyzer Benefits

  • Analysis in seconds: Real-time, continuous measurement suitable for process control applications with robust feedback control eliminating the need for complex feed-forward modeling.
  • No carrier gas or fuel gas requirements: Low operational costs for remote and unattended use with minimal infrastructure requirements making it suitable for small scale plants.
  • Robust calibration: Full hydrocarbon speciation without columns with less than 0.2% zero-drift per month.
  • Flow-through sensor design: No sensitivity to pressure and flow variations minimizes potential sampling and phase change issues.
  • Compact, outdoor-rated, low-power: Well suited for transportable spot check applications with a NEMA4X / IP66 enclosure that can be engine or manifold mounted.

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