Tuneable Diode Laser Absorption Spectroscopy (TDLAS)

Tuneable  Diode Laser Absorption Spectroscopy (TDLAS) All Tuneable Diode Laser Absorption Spectroscopy (TDLAS) products use the interaction between light and the molecules in a gas stream to determine the concentration of a given substance within that gas stream. In the case of the OptiPEAK TDL600, this is specifically water concentrations within a natural gas stream. To achieve this, the laser is precisely Tuneable by careful control of the laser operating temperature and drive current to emit light at the specific resonant wavelength of water in the near infrared region of the electromagnetic spectrum. The wavelengths used are specific to water molecules and therefore laser energy causes the water molecules to vibrate and absorb energy.

This effect can be used to calculate the concentration of water in a background gas. The gas is passed into a sample cell, where the laser light travels through the gas to a detector. If water is present in the sample, laser energy will be absorbed. Using digital processing techniques, the size of the ‘absorption peak’ can be very accurately measured and can therefore determine the concentration of water within the background gas.

This non-contact technology requires minimal maintenance, even in demanding applications such as changing methane concentrations or sour gas.

Fully hazardous area certified TDLAS moisture analyzer for measurement in natural gas and biomethane. OptiPEAK TDL600 employs the latest techniques in non-contact laser absorption spectroscopy to provide class-leading measurement performance, stability and detection sensitivity with minimum required maintenance.