Nir Spectrometry

Precursor of Near Infra Red (NIR) applied to hydrocarbon with more than 20 years experience in refining at BP, our intensive research program into NIR technology has lead to a portfolio of more than 40 patents. 
Topnir is the result of such a programme carried out between 1985 and 1995.
TOP stands for Topology and NIR for Near Infra Red. 

HYDROCARBON IDENTIFICATION BY NIR

The near infrared (NIR) spectral range can be divided in four different regions, a combination one and four overtones, which are spread between 4000 cm-1 and 14500 cm-1. Our interest has been focused on the combination region, adjacent to the medium infrared range, because it has been identified as the most informative part of the NIR range and the absorptions observed have the advantage to be significantly larger than for the overtones. It is thus possible to use a short pathlength of 500 microns which makes the cleaning and maintenance of the measurement cell much lighter.

All molecules can be seen as unique combinations of the C-H, C-C, O-H, S-H and N-H chemical bonds which have specific spectral signatures in the NIR spectral domain. Hence, two chemical mixtures of different nature or composition will always give two different NIR spectra as well as two persons have different fingerprints. The composition and the physical and chemical properties of a sample, i.e. its identity, can hence be derived from its NIR spectrum.