Question

Compare near IR and far IR spectroscopy, considering the type of transitions that are measured, and the availability of suitable detectors and optics.

Answer 1

Near IR spectroscopic method( NIRS) is spectroscopic method that uses the near infrared region of electromagnetic spectrum

from about 700 nm 2500 nm.

The far infrared spectroscopy involves 400-10 cm^-1( 25- 1000 micrometers), lying adjacent to the microwave , has low energy and may be used for rotational spectroscopy.

IR spectroscopy examins the molecular transitions.IR gives you possible functional groups ased on stretches, bending scissoring in the graph.

detectors used are:

photo electric detectors ( mercury cadmium telluride)

pyroelectric detectors

themal detectors