Teledyne 9110AH, Instruction Manual, Page: 167 / 181

TELEDYNE Model 9110AH NO
X
Analyzer Operator Manual, 01620, Rev. F
9-51
9.3.6.1 The PermaPure Drier
The PermaPure drier is constructed of 2 concentric tubes. The inner tube is a special material
that has an affinity for water vapor. The outer annulus is evacuated by the instrument pump.
This creates a concentration gradient causing water in ambient air to diffuse into the outer
annulus, thus the air in the inner tube becomes progressively drier as it progresses down the
tube.
Due to the large number of connections and fittings on the drier, the most common drier fault is
leaks. Before proceeding with any other procedures check the drier for leaks.
Occasionally the drier gets contaminated. The manufacturer of the drier recommends replacing
the drier rather than trying to clean it. If cleaning is chosen, the following options are available:
1. Dirt - Clean any solids from dryer inlet by brushing. Use clean dry air to blow any loose
particles from the inlet. De-ionized water or dilute (5-10% conc HCl in de-ionized water)
hydrochloric acid can be passed thru the dryer. This should be done only with the dryer and
HCl at room temperature.
2. Contamination with organic liquids and Freons - rinse the inner and outer tubes using 1,1,1
trichlorethane. Follow the solvent with dry air to purge the solvent.
3. Inorganic salts and oxgenated hydrocarbons can be removed by rinsing with 10% nitric acid
at 50 C.