UNI MP100 User’s Guide
8
4.5.2
Span Calibration
Span calibration determines the sensitivity of the sensor to the gas. Recommended calibration
gases and concentrations are listed in Section 7.7 at the end of this manual and in TA Note 4
(available at www.mpowerinc.com). Special calibration procedures for highly reactive gases are
described in TA Note 6. Oxygen sensor calibration is reversed from other sensors and uses pure
nitrogen with 0% oxygen during the span procedure and 20.9% oxygen (air) during the fresh air
“zero” procedure. We recommend using a fixed flow regulator of at least 0.3 LPM but no more
than 0.6 LPM. Use as short tubing connections as possible.
Span Calibration Procedure
1.
Connect the Calibration Adapter to the span gas cylinder’s regulator and snap it into place
over the UNI sensor.
2.
Enter the
menu, start the gas flow, and press the Left Key to start the calibration
count-down. The calibration time is typically 60 seconds but may be shorter or longer
depending on the sensor type.
3.
To abort the span calibration during count-down, press the Right Key and
is
displayed.
4.
After count-down, the span calibration result
or
is displayed.
5.
Turn off the gas supply and remove the Calibration Adapter.
CAUTION
During normal monitoring, never operate the MP100 with the Calibration Adaptor attached
because it will block diffusion of gas into the sensor.
