Question

6. (5 p) Indicate 2 advantages of the FTIR instruments over the dispersive instruments.

Answer 1

FTIR has advantages over dispersive instruments in terms of speed and sensitivity of the scans.

Advantages:

1. Multiplex advantage: (also known as Fellgett advantage)

In FTIR multiple number of scans can be done simultaneously whereas in dispersive instruments all the scans have to be done one after another which takes a lot of time.

2. Throughput advantage: (also known as Jacquinot advantage)

In FTIR the energy throughput(the amount of energy passing throught the system) is much greater than that of the conventional dispersive instruments because in dispersive instruments the energy throughput is limited by slits. This high energy throughput of energy results in higher Signal to Noise ratio.

Signal to noise ratio indicates the amount of desired signal to unwanted signal(noise). Higher the Signal to Noise ratio the better.