Fourier Transform Infrared

1. Fourier Transform Infrared

3. FTIR
 History
 Introduction
 Theory
 Technique
 Principle
 Working
 Working Diagram
 Actual Diagram
 Graph

4. FTIR
 History
infrared spectrophotometers were developed in the US in the mid 1940s. Initially,
their applications were confined to R&D work on organic compounds, mainly in
the petrochemical field. The first Japanese instruments were manufactured in
1954 by the Applied Optics Research Institute, the predecessor of JASCO.

5. FTIR
 Introduction:
A Fourier Transform InfraRed (FT-IR) Spectrometer is an
instrument which acquires broadband Near InfraRed (NIR) to Far
InfraRed (FIR) spectra.

6. FTIR
 Theory of FTIR:
 FTIR spectrophotometry was developed in order to overcome the limitations
encountered with dispersive instruments.
 The main difficulty was the slow scanning process. A method for measuring all the
infrared frequencies simultaneously, rather than individually, was needed.
 A solution was developed which employed a very simple optical device called an
interferometer. The interferometer produces unique type of signal which has all
the infrared frequencies “ encoded” into it.

7. Techniques of FTIR
 Following techniques of FTIR used by university researches scientists and process
engineers
 Attenuated Total Reflectance (ATR)
 Specular Reflectance (SR)
 Reflection absorption (RA)
 Transmission (TR)
 Photoacoustic (PA)

8. FTIR
 Principle
Principle Of FTIR is that many gases absorb IR radiation at species-specific frequencies.
FTIR spectroscopy is a disperse method, which means that measurements are performed over
a broad spectrum instead of a narrow band of frequencies.
The absorption corresponds specifically to the bonds present in the molecule. The frequency
range are measured as wave numbers typically over range 400-600m-1.

9. FTIR
 Working of FTIR
The FTIR uses interferometry to record information about a material placed in the IR
beam. The Fourier Transform results in spectra that analysts can use to identify or quantify
the material.

10. FTIR
 Working diagram:

11. FTIR
 Actual diagram

12. FTIR
 Graph

13. FTIR
• Applications of FTIR
• Quality verification of incoming/outgoing materials
• Deformulation of polymers, rubbers, and other materials through thermogravimetric infra-
red (TGA-IR) or gas chromatography infra-red (GC-IR) analysis
• Microanalysis of small sections of materials to identify contaminants
• Analysis of thin films and coatings
• Monitoring of automotive or smokestack emissions
• Failure analysis

14. FTIR