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Optional Equipment
Permeation Oven
Permeation Oven
Permeation Tube
Installation
9-2
Model 146i Instruction Manual
Since the temperature of the permeation tube oven should be stable, the gas
flow through the oven is small (approximately 150 sccm). The major
portion of the flow bypasses the oven, and is directed to the mixing chamber
with the stream from the oven. This is achieved by using the same
backpressure regulator described above for gas phase titration, with a
capillary of identical size.
During standby operation, a continuous flow of gas is necessary through the
oven. The standby flow and operating flow should be the same to +10
percent. This is achieved by setting the pressure regulator to the same
pressure setting as the backpressure regulator. In practice, rather than
measuring the pressure, it is the actual flows that are measured while
adjusting the pressure regulator. Two solenoids, under control of the
microcomputer, are used to change the flow of gas going through the oven
to the main-stream or to vent.
Use the following procedure to install the permeation tube.
1. Remove the oven cover.
2. Remove the glass chamber assembly by loosening the white plastic
retaining collar, loosening (not removing) the knurled screw, and gently
pulling the assembly upward. Completely remove the oven.
3. Separate the glass chamber from the top assembly by twisting and gently
pulling the glass away from the top.
Note Keep the glass clean when handling it.
4. Place the permeation tube(s) in the glass chamber.
5. Attach the glass chamber to the top assembly by gently pushing the two
together with a slight twisting motion.
Thermo Fisher Scientific
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Troubleshooting
