Linker IT Software
Google
Web www.oraxcel.com
menubar-top-links menubar-top-rechts
Home Help Search Login
Welcome, Guest. Please Login.
SQL*XL: Database to Excel bridge litLIB: Excel power functions pack ExcelLock: Locking and securing your valuable Excel spreadsheets encOffice: Protect your Excel file easy and safe encOffice: Protect your Excel file easy and safe
Pages: 1
Spectroscopy measurement techniques (Read 1485 times)
Gerrit-Jan Linker
YaBB Administrator
*****




Posts: 75
Spectroscopy measurement techniques
13.09.09 at 21:30:38
 
Spectroscopy measurement techniques
 
The energy balance for incident light may be written as follows according to the law of conservation of energy:
 
I0 = IA + IT + IR + IS
where:
I0 : Intensity of incident light.  
IA : Intensity of absorbed light.  
IT : Intensity of transmitted light.  
IR : Intensity of reflected light.  
IS : Intensity of scattered light
 
The light intensities I0 , IT , IR and IS can easily be measured by placing a detector at the corresponding position.  
 
All chemical information about the sample goes into IA , but this value cannot be measured directly. IA can only be accessed by evaluatingthe above equation.  
 
In all commercial spectrometers only one detector is used to measure a particular couple of intensity values (I0 and either IT , IR , or IS).
 
It is the goal of sample preparation to bring the remaining intensities to zero (or
at least very close to it).
 

  • Transmission measurements:
    Measured I0 and IT
    Aim of sample preparation:  IR = IS = 0
    Evaluation IA = I0 - IT
     
  • Reflection measurements
    Measured I0 and IR
    Aim of sample preparation: IT = IS = 0
    Evaluation IA = I0 - IR
     
  • Diffuse reflection measurements
    Measured I0 and IS
    Aim of sample preparation: IT = IR = 0
    Evaluation IA = I0 - IS
     

 
Measurement techniques:

  • 1 Transmission Measurements
  • 2 Reflection Measurements
    • 2.1 External Reflection  
    • 2.2 Reflection Absorption  
    • 2.3 Attenuated Total Reflection (ATR)  
    • 2.4 Reflection at Thin Films  
    • 2.5 Diffuse Reflection  

  • 3 Spectroscopy with Polarized Light  
    • 3.1 Optical Rotatory Dispersion  
    • 3.2 Circular Dichroism (CD)  

  • 4 Photoacoustic Measurements  
  • 5 Microscopic Measurements  
    • 5.1 Infrared Microscopes  
    • 5.2 Confocal Microscopes  
    • 5.3 Near-field Microscopes  


 
Source:
Handbook of Spectroscopy, G. Gauglitz, et. al.
Back to top
 
« Last Edit: 13.09.09 at 21:46:51 by Gerrit-Jan Linker »  

Gerrit-Jan Linker
Linker IT Software
Email WWW Gerrit-Jan Linker   IP Logged
Pages: 1