They operate on the principle of tunable diode laser adsorption spectroscopy (TDLAS), which uses highly tuned wavelengths of laser light from permanently fixed diodes in a cross-stack system to measure the concentration of gas species at the parts per billion (ppb) range. Leading continuous gas analyzers may also be capable of quantitively assessing the temperature, pressure, and velocity of observed samples.
TDLAS continuous gas analyzers can optically select measurements from samples across a single absorption line. A laser diode situated at one side of a stack scans through the gas stream and is detected by a receiver at the opposite side. This data is then analyzed at the near infrared (NIR) spectral range to determine the rate of absorption caused by sample gases. Intuitive software can then calculate the gas concentration and transmission rates within the stack for highly-automated in situ gas analysis and maintenance prediction. Assessing NIR spectra negates the likelihood of cross-sensitivity from alternate gas species that are incident to the measuring requirements.
The LS25 and LS4000 are ABB’s proprietary in situ cross-duct continuous gas analyzers. This blog post will explore the capacities and applications of these components in further detail:
Utilizing a transmitter/receiver configuration, the LS25 laser analyzer is designed to be diametrically mounted across a gas stack to measure gas concentration across a singular absorption line. The laser diode is temperature stabilized and the receiver is equipped with an automatically focusing lens to enhance the photo acquisition properties of the component.
The LS25 continuous gas analyzer is integrated into the modular Advance Optima system. This comprehensive gas analysis solution is equipped with an extensive range of data acquisition technology, including in-line tunable diode lasers for absorption spectroscopy and trace oxygen analyzers. It was engineered for practical use with potentially dangerous gas species and is approved to international certifications for application in hazardous locations.
With a similar configuration, the LS4000 is designed to measure gas concentrations through highly selective optical acquisition at the NIR spectral range. This continuous gas analyzer provides the highest precision under extreme conditions with ultra-low detection limits. The LS4000 standalone system is incredibly selective with virtually no cross interference from incident process gasses.
Both of these continuous gas analyzers have found application in some of the most demanding industrial applications worldwide, including power plants, co-incineration plants, and waste incinerators. They can suitably measure the flow of oxygen (O2), carbon monoxide (CO), carbon dioxide (CO2), and methane (CH4) in combustion systems with extremely sensitive measuring ranges.
ABB is a world leading supplier of industrial measurement instrumentation. We provide cutting-edge analytical technologies for severe process conditions so that operators can safely monitor the parameters of crucial processes in demanding facilities.
If you would like any more information about our TDLAS continuous gas analyzers, please do not hesitate to contact us using the links below.