Fourier transform infrared spectroscopy (FTIR) is used to identify minerals in core samples obtained during geotechnical investigation. FTIR measures the absorption of infrared radiation emitted by the test sample compared to its wavelength. The absorbed radiation excites the molecules into a higher vibrational state. Absorption bands indicate the type of minerals and their structure.
In trenchless technology, FTIR is used to analyze minerals in a sample of rock or soil obtained during a geotechnical investigation. For this test, usually a core plug is finely ground and a small quantity is taken and dispersed in a matrix of potassium bromide. The sample is then subjected to infrared radiation. The radiation’s effect is measured when it excites vibrations in the chemical bond within the sample’s mineral molecules. The transmitted radiation is then compared to standard spectral wavelengths for a range of minerals.