INFICON 2020ComboPRO Portable Photoionization Detector - Manual (Page 74)

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2020ComboPRO has drifted below zero. To readjust the display to zero, press the
TARE key, and the display will be re-set at 0.0.
Calibration Using Accessory Gas Bags
Preparing the Calibration Gas Bag and the Zero
Air Bag
WARNING
Observe proper handling techniques for all gases!
1. Connect the regulator to the calibration gas cylinder.
If you are using a portable tank of calibration gas, connect the regulator
directly to the tank.
If you are using a large cylinder of calibration gas, you must obtain a
high purity regulator. Isobutylene in air is usually supplied with a
standard CGA 590 cylinder valve outlet. Obtain a regulator with the
matching fitting. Connect the regulator to the tank of calibration gas.
Tighten the regulator onto the tank with a wrench. Do not over-tighten.
NOTE: Do not force the connection.
Do not use Teflon
®
tape with CGA fittings. In general, these fittings are designed for
metal-to-metal sealing.
Do not use adapters to connect one CGA fitting to another type of CGA fitting. If the
regulator does not match the outlet on your calibration tank, contact your specialty
gas supplier.
2. Attach the knurled nut on the gas bag adapter to the regulator. Finger-
tighten the fitting.