Toxalert TOX-O2-4 User Manual

TM

DATA

TOXALERT

SHEET

OXYGEN SENSOR MODEL TOX-O2

FEATURES

• 10 year sensing element life • Power indicator

• Low voltage circuits • Sensor failure indicator

• Linear 4 to 20 mA output • Loop current indicator

• Explosion Proof Housing • Interfaces directly to DDC systems

• Meets ASHRAE Std. 15-1994 • Relay output indicators

• Two Form C relay outputs

GENERAL DESCRIPTION:

The Models TOX-O2 oxygen sensors are an electrochemical cell
with extremely long sensor element life. The sensor element is the
self-powered, diffusion limited, metal-air battery type. The rate at
which atmosphere gases can get to the electrode through a diffusion
barrier is dependent on the concentration of gases (O
in the atmosphere. A voltage is generated that is proportional to
the rate of consumption of oxygen in the sensor cell.

in this case)

2

Most electrochemical sensors use a very thin plastic membrane
and have a short life. The TOXALERT oxygen sensor uses a heavy
membrane which allows gas to diffuse into the sensor making it
extremely robust and stable, plus it gives the element exception­ally long life expectancy, but still responds quickly to oxygen con­tent changes.

The model TOX-O
tor oxygen levels and to close “warning” contacts, when oxygen
levels drop to 19.5%, for the operation of ventilation equipment.
A second set of “alarm” contacts are provided to operate alarm(s)
and /or signal building management systems (BMS), when oxygen
levels drop to 18.5%. The warning and alarm setpoints are field adjustable.

The model TOX-O
a linear 4 to 20 mA output signal. This signal may be interfaced directly to a TOXALERT
control unit or any other standard BMS controller and provide actual percent oxygen concen­tration for control and/or display.

TOXALERT INTERNATIONAL, INC., P.O. BOX 159, MOUND, MINNESOTA 55364 [phone] FAX [phone]

/4 oxygen sensor/controller is designed to moni-

2

TOX-O2/1

/1 oxygen sensor/transmitter is designed to monitor oxygen levels and has

2

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GUIDE SPECIFICATIONS

MODEL TOX-O

/1 ANALOG SENSOR:

2

Provide an oxygen sensor(s) with a range of 0 to 25% and a linear 4 to 20 mA output signal over
its range. The sensors output shall be designed to work into a minimum of a 500 OHM load. The
sensor shall be housed in an industrial style explosion proof housing. The sensing element shall
be electro chemical diffusion barrier type and be designed for ten (10) year element life. Electro
chemical cells with a three year or less expected life are not acceptable. The sensor shall be 24 vdc
powered and its 4 to 20 mA output shall be directly proportional to the percent of oxygen being
detected. If the sensor should fail, it shall drive its output signal to zero indicating zero percent
oxygen and an alarm condition.

The oxygen sensor shall have the following diagnostic light emitting diodes (LED’s):

1) Power

2) Sensor failure

3) LOOP UP (LED varies in intensity indicating 4 to 20 mA loop current to controller).

Sensor shall have volt meter terminals on face of sensor to indicate percent oxygen being
detected.

MODEL TOX-O

/4 RELAY SENSOR:

2

Provide an oxygen sensor(s) with a range of 0 to 25%, have a 4 to 20 mA output signal and two
adjustable output relays over its range. The sensor shall be housed in an industrial style explosion
proof housing. The sensing element shall be electro chemical diffusion barrier type and be de­signed for ten (10) year element life. Electro chemical cells with a three year or less expected life
are not acceptable. The sensor shall be 24 vdc powered. If the sensor should fail, it shall drive its
output signal to zero indicating zero percent oxygen and energizing both output relays.

The oxygen sensor shall have the following diagnostic light emitting diodes (LED’s):

1) Warning relay energized

2) Alarm relay energized

3) Power

4) Sensor failure

The warning relay and alarm relay shall be Form C contacts and the relay setpoints shall be field
adjustable without calibration gas. Relay contacts shall be rated for 1 amp at 24 vdc.

Sensor shall have volt meter terminals on face of sensor to indicate percent oxygen being
detected.

TOXALERT INTERNATIONAL, INC., P.O. BOX 159, MOUND, MINNESOTA 55364 [phone] FAX [phone]

Visit our website at www. toxalert. com