Teledyne MX300 - Manual (Page 33)

Portable Oxygen Monitor Service Instructions
Teledyne Analytical Instruments 25
Table 3-1 Troubleshooting
Symptom Why What To Do
New sensor responds
slow or drifts. If the sensor is new
and was just removed
from its sealed bag it
may need to run for
several hours. A) Wait 1–2 hours and recali-
brate.
Sensor will not read be-
low 22 % after calibration
in 100% O2. Calibration in 100%
was invalid or the
room air enriched with
excess oxygen. A) Recalibrate using dry gas
B) Make sure that at least 6"
(30 cm.) of tubing is attached
to the exhaust side of the tee
adapter to prevent back fill-
ing. O2 flow rate should not
exceed 5 l/min.
C) Oxygen concentration at the
sensor is significantly higher
than 21%. Take the Monitor
to a well-ventilated area and
check the reading again.
D) Try calibrating with a known
good sensor, and if this fails,
contact customer support.
The sensor does not
react to changes in
oxygen concentration,
or the readings are un-
stable and drifting. Water may have con-
densed on the sens-
ing surface.
Electrical interference
is disrupting the elec-
tronics
A) Remove the sensor from tee
adapter and unscrew the plas-
tic flow diverter. Using absor-
bent tissue or cotton swab,
gently wipe off sensing sur-
face inside threaded portion of
sensor assembly. Do not
damage the sensing surface,
and do not leave any tis-
sue/swab residue on the
sensing membrane.
B) Relocate unit away from
sources of electrical noise
such as cauterizing equipment
and two-way radios.
The display is flashing
√ SENSOR
The unit has detected
a fault in the signal
from the sensor.
Sensor has expired.
The sensor has been
exposed to a gas con-
taining less than 18%
oxygen.
A) Check sensor cable con-
nections to ensure they are
completely inserted into the
mating connector and the
capture nut is firmly in
place.
B) Expose the sensor in 100%
O2 and check calibration.