Portable Oxygen Monitor

Portable Oxygen Monitor	Service Manual

Symptom	Why	What To Do
The unit has stopped	The MX300	A) Disconnect the batteries and
working and the LCD is	instruments are	inspect the contacts for
displaying	equipped with an	corrosion. Reconnect the
alphanumeric figures.	electronic "watch dog,"	batteries. If the unit functions
	which monitors the	properly, calibrate the unit
	circuitry within the unit	and reset the alarm values.
	for potential faults and	B) Try a new set of batteries.
	renders the unit	B) Try a new set of batteries.
	renders the unit
	inoperable until the	C) Increase the distance
	condition is corrected.	between the unit and any
	(See Watch dog	source of radio frequency
	section below)	interference. The sensor
	Several conditions can	cable is a prime source of
	Several conditions can	pickup as it can act like an
	activate the "watch	pickup as it can act like an
	activate the "watch	antenna. Relocate the
	dog." Dropping the	antenna. Relocate the
	dog." Dropping the	sensor cable and if possible
	unit, poor battery	sensor cable and if possible
	unit, poor battery	change its coiled length to
	connections, and radio	change its coiled length to
	connections, and radio	“de-tune” its antenna effect.
	frequency interference	“de-tune” its antenna effect.
	frequency interference	Placing the cable in a
	are the most common	Placing the cable in a
	are the most common	different position may also
	causes. See the watch	different position may also
	causes. See the watch	help.
	dog section for	help.
	dog section for
	additional information.

Alarm sounds/flashes	A) Readings are	A) Adjust high and low alarm
continuously.	outside alarm	setting to be above and
	limits.	below O2 value being
		displayed.
No display.	A) Batteries expired.	A) Check/replace batteries.
	B) Bad battery	B) Check battery connections.
	connection.	C) Calibrate.
		C) Calibrate.
Keys inoperable/cannot	The LOCK/UNLOCK	A) Press LOCK/UNLOCK key
turn unit off	key is activated which	once. LCD will flash
	is preventing key	indicating keys are active.
	operation
Cannot adjust	Critical settings require	A) If display is not flashing
calibration or alarm	two keys be pressed in	press lock key once to
settings	a specific order.	activate keys. Press desired
	LOCK/UNLOCK key is	function followed by the Up
	LOCK/UNLOCK key is	and Down key.
	active	and Down key.
	active

Note: In the event that none of these procedures produce desired results, remove the batteries and return the unit to Teledyne for repair.

Teledyne Analytical Instruments

Symptom