Teledyne TED-200 - Medical application oxygen monitor - Manual (Page 24)

3 Maintenance and Troubleshooting
Teledyne Analytical Instruments 3-4
Symptom
The oxygen reading fluctu-
ates or appears to be incor-
rect.
The unit appears to have a
momentary or intermittent
condition which causes the
alarms to activate; unit
cannot be silenced and all
keys are not functioning.
Why
Like all O
2
sensors, the T-7
detects the changes in the
partial pressure of O
2
. See
Appendix: Pressure.
The TED 200-T is
equipped with an elec-
tronic "watch dog," which
monitors the circuitry within
the unit for potential faults,
and may activate the alarm
and disable key functions.
The "watch dog" can be
reset only by disconnecting
the batteries.
Several conditions can
activate the "watch dog."
Dropping the unit, poor
battery connections, and
radio frequency interfer-
ence are the most common
causes.
What to Do
A) During calibration, make
sure there are no restric-
tions on exhaust side of
sensor. If the reading
changes with flow, the sen-
sor is pressurized or there
may be a leak in the sys-
tem.
B) If a high degree of accuracy
is desired, or the concentra-
tion of O
2
is in excess of
40%, calibration with 100%
is recommended.
C) If humidified gas is used to
ventilate the patient, water
vapor actually dilutes the
gas. See Appendix: Humid-
ity, Temperature.
D) If a blender is used, check
its calibration. See Appen-
dix: Discrepancy in Read-
ings.
A) Disconnect the batteries
and inspect the contacts
and wires for damage or
corrosion. Bend the battery
pack and connector con-
tacts slightly, if necessary.
Reconnect the batteries and
calibrate the unit. If the unit
appears to function prop-
erly, check the alarms and
settings. If the alarm contin-
ues or the unit does not
function, return the unit to
Teledyne for repair.
B) Replace batteries.
C) Increase the distance be-
tween the unit and any
sources of radio frequency
interference. Relocate the
sensor cable as conve-
niently as possible. Try dif-
ferent positions.