MKS Precisive®

Remote hydrocarbon qualification

Precisive® 5 Hydrocarbon Composition Analyzer is an on-line monitoring system configured for measurement of alkanes: methane, ethane, propane, butanes and pentanes. It is a real-time optical analyzer capable of accurately separating the C1-C5 hydrocarbon components; which previously could only be performed by Gas Chromatograph (GC) analyzers.

The Precisive® analyzer does not require carrier gas, fuel gases, or on-site calibration gases.  Sampling is a flow-through type, suitable for a continuous, on-line, unattended operation. With a low weight and small footprint, Precisive® can also be adapted for mobility and can easily be brought to various test sites for measurements in the field.

Areas of application

Composition analysis of C1 – C5 alkane (methane, ethane, propane, butanes and pentanes) gases is important in various applications within the LNG industries, with applications ranging from quality monitoring during production, custody transfer, to its use in power generation. Advanced process control technologies providing fast and accurate feed and product analysis are critical in optimizing efficiency and payback in various processing stages. In power generation applications, on-line and fast sensors are required to ensure optimum combustion efficiency and acceptable emission levels. Typical areas of application are:

  • Natural gas analysis (processing, transmission, storage, distribution)
  • Fuel analysis for engine control (gas turbines, internal combustion engines, fuel cell power plants)
  • LNG/LPG/BOG analysis
  • Wobbe Index metering for combustion control applications
  • Alternative fuels (Biogas, SynGas)
  • Ethylene production
  • Heating value and Wobbe measurements
  • Low-cost alternative to Gas Chromatography


Features and benefits

  • Flow-through analyser suitable for in-line measurements
  • Accuracy and repeatability equivalent or better than a gas chromatograph
  • Unattended remote monitoring or mobile unit
  • Real-time response (1-5 seconds)
  • Permanently calibrated
  • No carrier gas, no calibration gas
  • Low-zero drift (Maximum of 0,5 % throughout life of light source, ca. 18 months)
  • Low cost of ownership
  • >2500 units deployed
  • >350 years of cumulative run time


  • CSA Class 1 Division 2,
  • Groups A/B/C/D,
  • T4. ATEX Zone 2,
  • Ex nAnCIICT4Gc
  • IECEx


Calibrations and options

Permanent calibration options

The standard system configuration for Precisive® 5 hydrocarbon analysis provides measurements of up to 100% methane, 25% of ethane, 25% of propane, 10% of butanes and 5% of pentanes. Other ranges and/or additional gases are available, and specific calibrations are available for:

  • Natural gas
  • High-range C1-C4 with or without H2S
  • Acid & sour gas
  • LNG
  • LPG
  • Ethylene/Ethane
  • Propylene/Propane
  • CH4+CO+CO2
  • SynGas
  • Flare
  • Hydrocarbon processing
  • And more...

Analog inputs H2 and O2 (external).

Standard configuration of Precisive®

  • Precisive® Tunable Filter Spectrometer
  • Permanent Calibration according to application
  • Software including logging capabilities and control of Precisive ® TFS™
  • Custom-built gas cabinet including pressure regulators, heaters, gauges, filters, etc.

Options for Precisive®

  • Wireless communication capabilities
  • Automated control
  • Temperature control
  • Automated zeroing
  • Automated span check


Installation requirements

Precisive TFS™

Power 24 VDC (or external 250 VAC)
Sample Inlet ¼” Swagelok or custom
Sample Outlet ¼” Swagelok or custom
Sample pressure 0,1–5 psig or custom
Flow rate 0,1–2 L/min or custom
Communication Ethernet connection to Precisive TFS™
Dimensions 432 mm x 280 mm x 152 mm







Gas cabinet

Power 24 VDC (or external 250 VAC)
Span Gas Inlet (opt) Custom
Sample Inlet Custom
Sample Outlet Custom
Sample pressure Custom
Flow rate Custom
Communication Ethernet connection to Precisive TFS™
Wireless option available
Dimensions Custom