ABB Measurement and Analyser AO2000-LS25 Laser Analyser

General Purpose and Explosion Proof

Easy Measurement

This is a precision instrument It is a precision instrument using state-of-the-art electronics and laser technology.

Installation and maintenance The instrument requires care and preparation for installation and maintenance.

Measurement principle

The analyser is an optical instrument based on tunable diode laser absorption spectroscopy (TDLAS)

and is used for continuous on-site monitoring of gases in chimneys, pipelines, process chambers or similar.

The analyser measures the average gas concentration along the line-of-sight path using a

transmitter/receiver configuration (mounted in a relative diameter installation).

The measurement principle is infrared single line absorption spectroscopy,

based on the fact that each gas has a different absorption line at a specific wavelength.

The measurement principle is shown in Figure 1-1.

The laser wavelength is scanned over the selected absorption lines of the gas to be measured.

The absorption lines are carefully selected to avoid cross-interference from other (background) gases. 

Cross interference from other (background) gases.

The detected light intensity varies with the wavelength of the laser.

In the optical path between the transmitter and receiver, the target gas molecules absorb the laser wavelength.

Absorption of target gas molecules in the optical path between the transmitter and receiver.

In order to improve the sensitivity, wavelength modulation technique is used.

In order to increase the sensitivity, a wavelength modulation technique is used:

the laser wavelength is slightly modulated while scanning the absorption line.