INFICON 2020ComboPRO Portable Photoionization Detector - Manual (Page 76)

ISP-074-575-P1D 69 69
5. To close the gas bag valve, turn the knurled plastic knob counter-
clockwise to unlock it. Gently pull the valve tube up to close the valve.
Turn the knurled plastic knob clockwise to tighten it against the valve
tube.
Once the bag has been filled, use the bag and sample as soon as possible.
NOTE: Do not use gas bags to sample unstable or highly reactive compounds. Do not use
Tedlar® bags for storage of hazardous materials.
Figure 24. Using the Gas Bag
Calibrating the 2020ComboPRO with a Gas Bag
1. Ensure the short sample probe is connected to the 2020ComboPRO inlet. If
you are using the long probe for sampling, then ensure the long probe is
connected to the 2020ComboPRO.
NOTE: Ensure the sample probe is free of any contamination as this will affect the
calibration
2. Press the CAL key.
3. Follow the instructions on the display and connect the 2020ComboPRO to
zero air sample bag or leave the instrument unconnected so it can sample
clean ambient air. Then press the “Next” key. The 2020ComboPRO will
take 60-90 seconds to set the zero point for calibration.
Locking Ring
Tube Stub
Gas Bag Valve Injection Port
Septum Retainer
Replacing the Septum
Remove retainer and
replace silicone septum.
Place septum with
Teflon side down. Replace retainer
Do not overtighten.
Overtightening may result
in needle blocakge
Replace septum after
5-10 injections.To replace
septum, turn retainer counter-
clockwise. For replacement
septa order Teflon bonded to
Silcone, diameter = .375" (9.5 mm)