67
GC Injectors
DGAPermeationLoopAccessory
• For ExtractingandPreconcentratingDissolvedGases in liquid samples
• Built-inStandardsPreparationModule—MakeYourOwnStandards
• Requires aValveOven&oneor two10-port Valves
The Permeation Loop consists of permeationmembrane tubing encapsulated in a trap-heated glass tube.
When sample liquid is pumped through the permeation tubing, the dissolved gases therein selectively
permeate through theheatedmembrane into the surroundingextractionchamber, which isplumbedas the
loopof a 10-port gas sampling valve.
Waste
Sample
IN
Extraction chamber
Valve
Solenoid
valve 1
Solenoid
valve 2
Heliumpurge IN
HeliumpurgeOUT
Topviewof theDGA-TOGAPermeationTrapAccessory
PermeationTrap
Standards preparation
sparge head
Heated valve oven
with 10-port valve
inside
The Permeation Loop Accessory includes the
permeation trap, two peristaltic pumps, two solenoid
valves, and a standards preparation sparge head.
By reconnecting a few tubing lines, the DGA-TOGA
Permeation Loop Accessory can be conigured to
prepare dissolved gas standards. A Tedlar bag, or
other container, illedwith gas standard is connected
to the standard pump. The standards preparation
vessel is illed with sample liquid, such as water.
The standard pump bubbles gas standard into the
standards preparation vessel, equilibrating the liquid
over time to a known concentration.
8690-0087
DGAPermeationTrapaccessory
8690-0065
10-Port electrically actuated valve, plumbed& tested
8690-0088
Thermostatted valveovenmountedonan 8610CGC
