HIGH TEMPERATURE WARNING


Do not attempt to operate a White cell at high temperature. The reactive gases are in direct contact with the internal parts of the cell, and corrosion will take place. Hot reactive vapors and aerosols can eat the gold off the mirror surfaces. Stainless steel parts are also subject to corrosion at high temperature. Especially bad is the situation where the reactive gases are mixed with a high concentration of water vapor.


Chemists say that the rate of a chemical reaction doubles for every 10 degrees C. increase of temperature. If this rule holds all the way up, it means that if you raise the cell temperature by 100 degrees C., the corrosion reactions will speed up by a factor of 1000! Glass and epoxy can usually withstand the attack by high temperature vapors and aerosols, but metal parts cannot.


Cells from Infrared Analysis, Inc. can be heated mildly, (say, to 50 Deg. C.) if they are clean and dry. Warming the cell while pumping on it is sometimes necessary to rid the walls of adsorbed molecules, like H2O, CO2, or NH3. However, actual cell operation should always be carried out at normal room temperature. If condensation of hot vapor is of concern, the sample should be diluted with nitrogen.


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