Evolved gas detection

Evolved Gas Detection iEGD). This term covers any technique of detecting whether or not a volatile product is formed during thermal analysis. Evolved Gas. 4 mi lysis (EG.4). A technique of determining the nature and amount of volatile product or products formed during thermal analysis. 

With the controlled atmosphere heated sample holder, it was a simple matter to connect a thermistor-type thermal conductivity cell to the system and, by means of an external multichannel recorder, record the DRS and the evolved gas detection lEGD) curves simultaneously (17). This modification of the apparatus is shown in Figure 9.4. The cell was connected to a Carle Model 1000 Micro-Detector system by means of metal and rubber tubing. The thermal conductivity cell was enclosed by an aluminum block which was heated to 100 C bv means of a cartridge heater. The block was connected to a preheat chamber, also operated at 100 C, which was used to preheat the helium gas stream before it entered the detector. The output from the detector bridge was led into one channel of a four-channel 0-5 mV Leeds and Northrup multipoint strip-chart potentiometric recorder. The temperature programmer from a Deltatherm III DTA instrument was used to control the temperature rise of the DRS cell. Output from the Beckman Model DK-2A... 

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