Teledyne T100 Manuale Utente

This section describes the principles of operation for the T100 SO

2

 analyzer (Section 

13.1), for the optional O

2

 sensor (Section 13.2) and for the optional CO

2

 sensor (Section 

13.3). It also describes the principles of operation for pneumatics (Section 13.4), 
electronics (Section 13.5), communication interfaces  (13.6) and software (13.7). 

The T100 UV Fluorescence SO

2

 Analyzer is a microprocessor controlled analyzer that 

determines the concentration of sulfur dioxide (SO

2

), in a sample gas drawn through the 

instrument. It requires that sample and calibration gases be supplied at ambient 
atmospheric pressure in order to establish a constant gas flow through the sample 
chamber where the sample gas is exposed to ultraviolet light; this exposure causes the 
SO

2

 molecules to change to an excited state (SO

2

*). As these SO

2

* molecules decay into 

SO

2

 they fluoresce. The instrument measures the amount of fluorescence to determine 

the amount of SO

2

 present in the sample gas. 

Calibration of the instrument is performed in software and usually does not require 
physical adjustments to the instrument. During calibration, the microprocessor measures 
the sensor output signal when gases with known amounts of SO

2

 at various 

concentrations are supplied and stores these measurements in memory. The 
microprocessor uses these calibration values along with other performance parameters 
such as the PMT dark offset, UV lamp ratio and the amount of stray light present and 
measurements of the temperature and pressure of the sample gas to compute the final 
SO

2

 concentration. 

This concentration value and the original information from which it was calculated are 
stored in the unit’s internal data acquisition system and reported to the user through a 
vacuum fluorescent display or as electronic data via several communication ports. 

This concentration value and the original information from which it was calculated are 
stored in the unit’s internal data acquisition system (refer to Section 0) and reported to 
the user through a vacuum fluorescent display or several communication ports. 

The physical principle upon which the T100’s measurement method is based is the 
fluorescence that occurs when sulfur dioxide (SO

2

) is changed to excited state (SO

2

*) by 

ultraviolet light with wavelengths in the range of 190 nm-230 nm. This reaction is a two-
step process.  

06807C DCN6650