Near-Infrared (NIR) Spectroscopy

Description

The near infrared (NIR) occurs at frequencies of 1.2x10^14-4x10^14 Hz, with wavelengths between 700 and 2500nm. While fundamental molecular vibrations occur in the MIR range, vibration overtones and combination bands can be detected in the NIR range. NIR instrumentation is field portable and less expensive, and is therefore employed in PSS applications.

Applications

NIR can be used to measure soil water content, carbon, texture (clay minerals), iron-oxides and a number of other correlative parameters (e.g. CEC).

Limitations

Development Status

Commercial

Resources

References

1. Shepherd, K.D., Walsh, M.G., 2007. Review: Infrared spectroscopy-enabling an evidence-based diagnostic surveillance approach to agricultural and environmental management in developing countries. Journal of Near Infrared Spectroscopy, 15(1), 1-20.

2. Ben-Dor, E., Taylor, R. G., Hill, J., Dematt, J. A. M., Whiting, M. L., Chabrillat, S., Sommer, S. & Donald, L. S. (2008) Imaging Spectrometry for Soil Applications. Advances in Agronomy. Academic Press.

3. Viscarra Rossel, R. A., Cattle, S. R., Ortega, A. & Fouad, Y. (2009) In situ measurements of soil colour, mineral composition and clay content by vis-NIR spectroscopy. Geoderma, 150(3-4), 253-266.