Determining Release Rate By Transfer Standard - Thermo Scientific 146i Instruction Manual

Determining Release Rate
by Transfer Standard
Thermo Fisher Scientific
5. Carefully remove the permeation tube from the oven and weigh to an
accuracy of 0.1mg. Perform this measurement as quickly as possible.
6. Replace the permeation tube into the oven of the instrument.
7. Repeat Steps 5 and 6 after two weeks.
8. Compute the weight loss of the permeation tube from the values
determined in Steps 5 through 7.
9. Repeat Steps 5 through 8 until the weight loss has been determined to a
precision of 1-2%.
10. For the most accurate work, use the permeation tube in the same oven
that was used to determine the weight loss of permeation tube.
Use the following procedure to determine the release rate by transfer
standard.
1. Make sure the oven has been calibrated as described in the "Permeation
Tube Oven Calibration" procedure described previously. Also make sure
that the Transfer Standard has been properly calibrated.
2. Determine the permeation rate for the permeation tube in the Transfer
Standard, or install a certified permeation tube.
3. Allow the permeation tubes in both the 146i and the Transfer Standard
to stabilize for at least 48 hours.
4. Carefully calibrate the 146i using the Transfer Standard. The output of
the Transfer Standard should be connected to the SAMPLE bulkhead
on the rear panel of the 146i.
5. Switch the calibrated 146i into the span mode.
Optional Equipment
Permeation Oven
Model 146i Instruction Manual 9-9