Thursday, November 12, 2015

Remote Sensing of Gases Directly in the Process

Electric power plant
Electric Power Plant
Industrial operations, whether for direct process control or emissions compliance monitoring, have a need for accurate, reliable measurement of specific gas concentrations within a flowing medium. Tunable diode laser spectroscopy, packaged for industrial use, provides a number of substantially positive attributes.

  • Rapid measurement.
  • Can be focused on a specific component of interest.
  • Multi-channel operation provides analysis of several components.
  • In situ installation can provide direct measurements within a stack, pipe, or duct without sample handling or conditioning.
  • Can measure NH3, HF, HCl, H2O, CO, CO2.
  • Internal reference cell provides long term stability.
  • Some models have continuous automatic calibration.
Siemens manufactures a line of tunable diode laser gas analyzers for industrial applications. In the company's own words, here is a basic description of how it works.

As a tunable diode laser-based technology this in-situ device enables high-performance measurements. The sensors (transmitter and receiver) are meant to be mounted directly on the process with no need of sampling systems. Laser light is sent from the transmitter, passing through the process gas, arriving at the detector on the receiver side. The measurements are carried out on-line with a very short response time permitting fast and effective cost-savings in process control. The laser characteristics allow single-line spectroscopy free of interferences. Since the band width of the laser light is extremely narrow, only the gas component of interest will interact with it. Other process influences, such as dust and temperature, are easily eliminated due to the excellent inherent compensation capabilities of this technique.


There is application assistance and more detailed information available from knowledgeable sales engineers in all localities. Combine your process mastery with their product application resources to meet the challenges posed by modern industrial process operation.