09419A DCN8342
Teledyne API Model 480L 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 In” port of the monitor. 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 full scale range in magnitude.
5.2.3.3
S
PAN
C
ALIBRATION
The span calibration allows the instrument to calibrate its internal slope factor based
on the source of ozone with a known ozone concentration. Connect the source to the
SAMPLE IN port of the monitor. Allow the instrument to stabilize on the span gas
source for a minimum of 1 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 arrows 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.
Summary of Contents for 480L
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