Model CXT-DM
CXT-DM Instruction Manual
Rev. 2.0
Page 16 of 54
2.
After the initial power up the sensor display will turn off. Thereafter the display will come on once
every 10 seconds and will display the current reading for about 2 seconds, and will return to a blank
display to conserve battery power.
NOTE
: In normal operation the display will come on once every 10 seconds, will display the
current reading for about 2 seconds, and will return to a blank display to conserve battery
power.
Initial Operational Tests
After a warm up period of 1 hour (or when zero has stabilized), the sensor should be checked to verify
sensitivity to the target gas.
Material Requirements
•
Detcon PN 613-120000-700 700 Series Splash Guard with integral Cal Port and Calibration Wind
Guard (P/N 943-000000-000) -OR-
•
Detcon PN 943-000006-132 Threaded Calibration Adapter - OR -
•
Detcon P/N 943-01747-T05 Teflon Calibration Adapter for highly reactive gases
•
Detcon Span Gas; 50% of range target gas in balance N
2
or Air at fixed flow rate between 200-
500cc/min
NOTE
: Calibration gas generators using perm tubes or electrochemical sources may be used in
place of span gas cylinders.
NOTE
: Wind Guard must be used when calibrating with the integral cal port to ensure proper
calibration.
1.
Attach the calibration adapter to the Splashguard Adapter Assembly or connect tubing to integral cal
port. It is recommended that the Wind Guard (Detcon P/N 943-000000-000) is installed over the
Splash Guard during calibration. Apply the test gas at a controlled flow rate of 200 - 500cc/min
(500cc/min is the recommended flow). Observe that the ITM display increases to a level near that of
the applied calibration gas value.
2.
Remove test gas and observe that the display decreases to “0”.
3.
If a calibration adapter was used during these tests, remove them from the unit, and re-install the
Splash Guard. If the wind guard was used, remove the wind guard.
Initial operational tests are complete. CXT-DM toxic gas sensors are factory calibrated prior to shipment, and
should not require significant adjustment on start up. However, it is recommended that a complete calibration
test and adjustment be performed 16 to 24 hours after power-up. Refer to zero and span calibration
instructions in Section 3.3 Calibration.
2.6.2
O
2
Deficiency Sensors
a)
When first powered up the CXT-DM display should read close to 20.9%.
b)
The reading should stabilize within 1 to 2 minutes of power-up (assuming a ‘normal’ ambient O
2
concentration).
Initial Operational Tests
After a warm-up period of 5 minutes the sensor should be checked to verify response to O
2
deficiency.