Hazardous Area
X-STREAM O
2
Transmitter
5-6
Instruction Manual
IM-106-910C, Rev. 1.0
November 2009
1. Make sure that the calibration gas line is capped tightly between
calibrations. If autocal is used, make sure the check valve is seating
properly.
2. A leak in the Oxycore viton o-ring seal can allow ambient air to migrate
down the annular space between the sensor core and probe tube, and
then into the cell. Always inspect the viton o-ring when removing and
reinstalling the Oxycore sensor core.
Figure 5-2. Probe Leakage Paths
Internal Reference Air Leak -
There may be a leak inside the Oxycore
sensor core itself, permitting the reference air (20.95% O
2
) to mix with the
process gases at the cell. To confirm this leak condition, pressurize the inside
(reference side) of the probe by plugging the reference air exhaust port with
your finger for 1 minute. (the conduit ports where the signal and power wires
pass may also need to be sealed.) The O
2
reading should decrease slightly. If
the O
2
reading increases during this test, there is a leak inside the probe.
1. Acid condensation inside the probe can degrade the cal gas hose
(25, Figure 6-5) that carries the cal gas to the cell. Inspect this hose.
See Figure 5-2. Dislodging or improper installation of the cal gas or
reference air hose can cause a leakage path.
2. The sensing cell (4, Figure 6-1) is fastened to the end of the probe tube
and uses a corrugated washer (3, Figure 6-1) to separate the process
gases from the ambient reference air. The corrugated washer may be
damaged by corrosion. Discard used washer.
