Rae UltraRAE 3000, User Manual

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UltraRAE 3000 User’s Guide
20.1 Span 2 Calibration
A cylinder of standard reference gas (span gas) fitted with a 500
cc/min. flow-limiting regulator or a flow-matching regulator is the
simplest way to perform this procedure.
Note:
This gas should be of a higher concentration than the gas used
for Span 1 calibration.
Choose the 500 cc/min. regulator only if the flow rate matches or
slightly exceeds the flow rate of the instrument pump. Alternatively,
the span gas can first be filled into a Tedlar bag or delivered through a
demand-flow regulator. Connect the calibration adapter to the inlet
port of the instrument, and connect the tubing to the regulator or
Tedlar bag.
Another alternative is to use a regulator with >500 cc/min flow but
allow the excess flow to escape through a T or an open tube. In the
latter method, the span gas flows out through an open tube slightly
wider than the probe, and the probe is inserted into the calibration
tube.
At the Span Calibration menu, you perform a Span calibration. You
may also go back to the Zero calibration menu or to the initial
Calibration menu if you want to exit calibration.
•
Press [Y/+] to enter Span 2 calibration.
•
Press [N/-] to skip Span calibration and return to Zero
calibration.
•
Press [MODE] to exit Span calibration and return to the top
calibration menu.
If you have pressed [Y/+] to enter Span calibration, then you will see
the name of your Span gas (the default is isobutylene) and the span
value in parts per million (ppm). You will also see this message that
prompts you:
Please
apply gas...
4. Turn on your span calibration gas.
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