PROGRAMMING
4-9
4.4.2
Span Calibration
This procedure determines the second point of the sensor
calibration curve for the sensor. 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. 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
MiniRAE 2000 Monitor, 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.
Before executing a span calibration, make sure the span value
has been set correctly (see next sub-menu).
1.
Make sure the monitor is connected to one of the span gas
sources described above.
2.
Press the
[Y/+]
key at the “Span Cal?” to start the
calibration. The display shows the gas name and the span
value of the corresponding gas.
3.
The display shows “Apply gas now!” Turn on the valve of
the span gas supply.
Summary of Contents for MiniRAE 2000 PGM-7600
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