Ametek Thermox 2000 ATEX Series User Manual page 83

If you find that a regular calibration isn't working correctly, first
check that your calibration gas values match the values written on
the gas cylinders; also be sure that the correct flow of gases has been
set and that the gases are allotted enough time to flow through the
sensor. Only if these checks have been done and the system still can't
be properly calibrated should you perform a primary calibration.
Setting up a primary calibration
Make sure you have properly entered your calibration gas values by
using the Cal Gas Values option from the Calibrate key before starting
your primary calibration.
1. Select Primary Calib from the Setup key.
2. If you have the auto calibration card option (and a remote calibration
unit), you will be prompted to select Auto Calibrate, Remote Cali-
brate, or Manual Calibrate. If you don't have the auto calibration
option, you will be placed into a manual calibration, where you will
be told to inject your span gas into the calibration gas inlet port.
From this point, operations work as they do for a regular calibration.
Please see the "Initiate Cal/Initiate Verify" section in Chapter 5 for help
on how to perform the calibration. Note that if you have the combus-
tibles option, during a primary calibration the system will not use the
combustible span gas to calibrate the system.
Upon completion of the primary calibration, the system will notify
you that a standard calibration is required by displaying a Calibration
Required message (see chapter 5 for help on how to perform a
standard calibration).
Oxygen readings on the display will not be accurate until the regular
calibration is performed.
In addition, a 15 minute recovery time follows the primary calibra-
tion to allow the cell to stabilize. After this 15 minute stabilization
period, perform the regular calibration.
During the recovery time immediately following the primary
calibration, you may see some temperature related error messages.
You can ignore these messages and assume no problem exists. This
NOTE
is because after a primary calibration, the cell temperature is
adjusted.
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