TELEDYNE API 480M, Руководство пользователя

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09420A DCN8343 Teledyne API Model 480M O
3
Monitor User Manual 33
5.2.3.2. Z
ERO
C
ALIBRATION
The zero calibration allows the instrument to calibrate its internal ozone offset
factor. This should only be done with a source of zero air, free of ozone, connected
to the sample inlet. Allow the instrument to stabilize on the zero air source before
attempting to zero. This normally takes 10-15 minutes.
From the Cal menu, press the control button under the “Zero Cal” field to enter the
Zero Calibration menu. Follow the prompts on the screen, and when ready to start
the calibration, press the button under Execute cal. To abort the calibration, press
the Back button, which returns the display to the previous menu level. Once
calibration begins, the instrument will complete the calibration and adjust the
appropriate Vars.
Returning to the Default Screen should show the concentration display at zero.
Please note that while measuring zero air, a certain amount of noise or “dithering”
of the concentration about the zero point will occur and is normal. This noise is
typically ±0.5% of the full scale range in magnitude.
5.2.3.3. S
PAN
C
ALIBRATION
The Span Calibration also allows the instrument to calibrate its internal ozone offset
factor. This calibration, however, is done with some controlled concentration gas
connected to the sample inlet. It is recommended that the span gas is concentrated to
around 80% of the operating range. Allow the instrument to stabilize on the span
gas source for at least one hour before performing the span calibration.
Note
A Span Calibration should only be performed with a precision
source of ozone calibration gas. Simple ozone generators
without a measurement feedback system should never be used
for performing span calibrations.
If you are unsure regarding the suitability of a particular source
of calibration gas, contact Technical Support at Teledyne API for
assistance.
In the Diag>Cal>Span Cal menu, use the buttons under the Up/Down arrow fields
to set the Span Target concentration (the actual concentration of ozone being
supplied to the monitor) and press the Enter button, then press the button under the
Execute cal field to perform the span calibration or press the Back button to abort
the cal process
If the calibration is successful, the display will return to the concentration menu and
the monitor reading should change adjust to read very close to the target value. If
the calibration cannot be performed, a Cal Status Failed message will be displayed
and you will need to return to the start of the Span Cal menu.
If the Cal Status Failed message occurs, it means the Span Cal cannot be performed
because it would result in an out of range slope value for the monitor. This means
that either the sensor in the monitor is malfunctioning, causing improper readings,
or the actual ozone concentration being supplied to the monitor is different than the
target value being entered.