Cambridge Sensotec Rapidox 1100E Oxygen Analyser Instruction Manual
Version 3.8
7
Last printed 29/08/2012 16:01:00
a cylinder of known composition. For accurate calibration it is important to
allow sufficient time to flush the sensor properly. Wait for the top line of
the display (1) to become stable. To complete the calibration press and
hold the ENT button for two seconds. During this time you will see a bar
graph progress across the lower display. The analyser will then recalibrate
and display “O
2
Calibrated” and then return to normal run mode. The
display will now correctly read the value of the first calibration gas. Note
that if the ENT button is released before two seconds have elapsed, the
recalibration will be aborted and when the analyser eventually returns to
run mode it will use the existing calibration.
3)
Note that the analyser should ideally be calibrated at normal ambient
pressure and at the temperature at which it will be used. If the pressure
correction mode is set to AUTO then it is still possible to perform an
accurate calibration at pressures other than ambient. If the gas temperature
is significantly different from the ambient temperature, allow the gas to
flow for sufficient time for the sensor temperature to stabilise fully before
calibrating.
4)
The analyser predicts the correct signal from the sensor during calibration
and if this is outside the range of expected values then the display will flash
and display “G?” to warn you that either the cal gas flowing over the sensor
is different to the value you have programmed OR the sensor may be old
and approaching the end of its life. Check before proceeding!
5)
To calibrate using the second calibration gas, repeat the procedure from 2
but this time press ENT followed by the UP or DOWN button to scroll
through to the “O
2
Low” screen. Flush the sensor chamber with the second
calibration gas allowing several minutes for the new gas to flush through.
Wait for the display to become stable before pressing the ENT button for
two seconds. The analyser will then recalibrate and display “O
2
Calibrated”
and then return to normal run mode. The display will now correctly read
the value of the calibration gas.
6)
The analyser is now correctly calibrated and will read accurately between
these two calibration points. Note that this procedure can also be
performed remotely using the software described in section 8.
7)
If at any time, you encounter difficulties and wish to restore the machine to
its factory set calibration, use the configuration software provided and load
the original factory settings (described in section 6.15 below). Each
machine is provided with a unique file that contains the factory settings.
This is located on the CD-ROM provided and is copied onto your PC during
the installation process.
8)
Note that the two calibration points are independent of each other so you
can calibrate the analyser in any order you desire. However please note
that ‘O
2
High’ must always be greater than ‘O
2
Low’. Typically the factory
settings are ‘O
2
High’ = 20.95% and ‘O
2
Low’ = 0%.
Summary of Contents for SENSOTEC Rapidox 1100E
Page 46: ......
