Teledyne t320u Manuale Utente

Theory of Operation 

Teledyne API – Model T300/T300M CO Analyzer 

I

 is the intensity with absorption.   

L

 is the absorption path, or the distance the light travels as it is being absorbed.   

C

 is the concentration of the absorbing gas;  in the case of the T300/T300M, Carbon 

Monoxide (CO).   

α

 is the absorption coefficient that tells how well CO absorbs light at the specific 

wavelength of interest.   

 

In the most basic terms, the T300/T300M uses a high-energy heated element to generate 
a beam of broad-band IR light with a known intensity (measured during instrument 
calibration).  This beam is directed through multi-pass cell filled with sample gas.  The 
sample cell uses mirrors at each end to reflect the IR beam back and forth through the 
sample gas a number of times (see Figure 13-1).   

The total length that the reflected light travels is directly related to the intended 
sensitivity of the instrument.  The lower the concentrations the instrument is designed to 
detect, the longer the light path must be in order to create detectable levels of 
attenuation. 

Lengthening the absorption path is accomplished partly by making the physical 
dimension of the reaction cell longer, but primarily by adding extra passes back and 
forth along the length of the chamber. 

T300 

32 

437.5 mm 

14 Meters 

T300M 

8 

312.5 mm 

2.5 Meters 

 

06864B DCN6314