300  AO2000 CONTINUOUS GAS ANALYZERS  |  OI/AO2000-EN REV. B 
 
 
 
Limas11 IR, Limas21 UV: Safety cell cleaning 
Description of the safety cell   
The safety cell comprises three components: 
•  Sample cell of stainless steel 1.4571, 
•  Beam guide tube 1 of brass (on the side pointing to the beam splitter), 
•  Beam guide tube 2 of brass (on the side pointing to the measuring de-
tector). 
The beam guide tubes are screwed into the sample cell and press the cell 
window against the clamped 22.1x1.6-FFKM70 O-ring seals. In this manner, 
the sample gas side of the cell is sealed so that it is gas-tight. One 
28x2-FKM80 O-ring seal is located on the periphery of each of the beam 
guide tubes. The purge gas chamber is sealed so that it is gas-tight to the 
outside by means of this seal. 
The tightness of the sample cell has been tested in the factory for a leakage 
rate of < 1 x 10
−6
 mbar l/s.