Ametek Thermox CEM O2/TM, User Manual

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Maintenance and Troubleshooting | 6-15
Calibration Gas Time Inadequate
If you are having problems running an auto calibration, you may not have
allowed the calibration gases enough time to flow through the sensor and
stabilize. To correct this problem:

Select the Inject Cal Gas option from the Calibrate Key menu.

Turn on each calibration gas and determine how long it takes for each
gas to stabilize on the control unit display. Then add a one-minute
buffer to each of these times. Also make sure the cylinder regulators
are set to correct pressure. See the Flow Section of the System Inter-
connect Drawing for the system flow and pressure requirements—this
drawing is included with your Installation package.
Select the Cal Gas Duration option from the Calibrate/Set Cal Timers
menu to set calibration gas times.
If performing a manual calibration, ensure that you are waiting for the
reading to stabilize on the display before switching to the next calibration
gas.
AC Power Checks
loss / inadequate AC voltage to the sensor
Measure the AC voltage to the sensor board at terminals L1 and L2.
Ensure that this voltage is sufficient. Check the measurement technique
employed by the volt meter (for example, RMS, average, peak, etc.). Speci-
fications are based on RMS measurements.
Furnace Checks
Open furnace
Disconnect power to the control unit and the sensor. With an ohm meter,
measure across terminals “R” and “S” on the sensor board. The resistance
of the furnace should be 32 ohms (+/- 10%) at room temperature. Add 5%
if the furnace is still hot.
If the furnace resistance is not within allowable tolerances, replace the
furnace.
NOTE
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