PROGRAMMING
4-8
4.4.1
Fresh Air Calibration
This procedure determines the zero point of the sensor
calibration curve. To perform a fresh air calibration, use
the calibration adapter to connect the MiniRAE 2000 to a
“fresh” air source such as from a cylinder or Tedlar bag
(option accessory). The “fresh” air is clean dry air without
any organic impurities. If such an air cylinder is not
available, any clean ambient air without detectable
contaminant or a charcoal filter can be used.
1. The first sub-menu shows: “Fresh air Cal?”
2.
Make sure that the MiniRAE 2000 is connected to one
of the “fresh” air sources described above.
3.
Press the
[Y/+]
key, the display shows “zero in
progress” followed by “wait..” and a countdown timer.
4.
After about 15 seconds pause, the display will show the
message “zeroed… reading = X.X ppm…” Press any
key or wait about 20 seconds, the monitor will return
back to “Fresh air Calibration?” submenu.
Note:
The charcoal filter has a check box so that user can
mark off a box each time the filter has been used. The
charcoal filter should be replaced after 20 calibrations.
