Introduction 
8  Agilent Cary 630 FTIR Spectrometer User’s Guide 
The Cary 630 FTIR uses technology known as Fourier transform 
infrared (FTIR) spectroscopy, which is the current state-of-the-art 
technique for molecular compound identification and quantification. 
FTIR uses an infrared light source to pass through the sample and 
onto a detector, which precisely measures the amount of light 
absorbed by the sample. This absorbance creates a unique spectral 
fingerprint that is used to identify the molecular structure of the 
sample and determine the exact quantity of a particular compound in 
a mixture. At the heart of the Cary 630 FTIR spectrometer is a unique 
Michelson interferometer. This proprietary design is the key to making 
FTIR technology compact, lightweight and rugged. 
The Cary 630 FTIR is available in two configurations depending on the 
frequency range necessary for your application. Please see the Cary 
630 FTIR specifications for details. 
In addition, a number of different sampling accessories are available 
to suit various sample types and sensitivities. The accessories 
accommodate the analysis of a range of liquids, powders, gases, pastes 
and gels. They include: 
  Diamond ATR: For the chemical analysis of liquids, powders, 
pastes and gels. The attenuated total reflectance (ATR) system is 
available as a single-reflection (most common) ATR. 
  ZnSe ATR: For the chemical analysis of liquids, gels and soft 
solids within a pH range of 5-9. The attenuated total reflectance 
(ATR) system is available as a single-reflection ATR (most 
common) and a multi-bounce ATR (Liquids only)  
  Transmission: A classic infrared sampling interface, allowing 
measurement of solids, liquids and gases. A 50 mm slide-mount 
gas cell is also available from Agilent. 
  TumblIR: Single pathlength transmission for rapid chemical 
analysis of liquids under ambient conditions. 
  DialPath: For rapid chemical analysis of liquids under ambient 
conditions, with three set pathlengths that allow you to choose the 
sensitivity necessary for your analysis. 
  Diffuse Reflectance: For quantitative and qualitative 
measurement of powdered and solid samples. Provides more 
sensitive quantitative analysis than ATR, while still being easy to 
use.