The Tunable Diode Laser Absorption Spectroscopy is a technique which is also known as TDLAS. It is mainly responsible for the exploitation of rotational vibrational absorption. As the name describes this concept is rises from the laser spectroscopy, which covers the topic of trace gas detection. The brief description of TDLAS is mention as a method for measuring the absorption of given varieties such as water vapor, methane and much more are there. All this takes place at a time of gaseous mixture while using tunable diode lasers as well as laser absorption spectrometry. The key features of this technique are there in nanoplus.com which can provide a brief idea. Talking about its measurement techniques it is mainly responsible for measuring pressure, temperature, velocity as well as the mass flux of a gas under observation. Laser absorption spectrometry is a leading technique used for quantitative evaluation process of atoms as well as molecules in a gas phase.
Talking about the mathematical expression velocity and the temperature is calculated by the easy and simple process given below. Considering a gas at an absorption feature of specific wavelength:
I (ν, t) = I0 (ν) e-S (T) g (ν, ν0) n L
Here one can see the transmitted intensity declines exponentially with:
In above equation, n is the number of density (molecular absorbers)
I0 (ν) is initial laser intensity
I (ν, t) the intensity detected after the probe with an absorption length L.
The emission wavelength of the tunable diode laser is VCSEL and DFB. Talking about its measurements based on above expression is: this is a highly sensitive technique which involves detection process of ppm to ppb level concentrations. In nanoplus.com concept of TDLAS is there with mathematical expression. In given formula the whole details of process take place in transmission of light through a gas is there.
One will also get the descriptive information of product attenuation coefficient of gas from the provided link. Moreover this will also explains the distance of light travelling through the gas. Standard Nanoplus|Tunable Diode Laser Absorption Spectroscopy consists of a wavelength tuning DFB laser, which is an emitting monochromatic light position at the absorption line to trace gas. Further an optical lens for the laser light operation is used. A gas sample cell filled with H2O is preferable. At last a photo detector for measuring laser light is applicable.