SF6 P2 Instrument User Manual V1.2
Unrivalled Gas Detect
ion.
Page 11 of 16
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O2 sensor
Functionality
The optionally available O2 sensor continuously measures the O2 content in the ambient air, and reports it to the
network controller if present.
An alarm condition on both the measuring station and network controller is raised whenever the oxygen level is
outside the allowed range of 16…25%.
Physical location
The O2 sensor is part of the SmartSensor, it is found protruding downwards from it.
Sensor Type
The O2 sensor is of galvanic cell type. It exhibits low cross sensitivity to CO2 and other gases, good stability and
linearity over its range.
Sensor Lifetime
With a reasonable safety margin, sensor life is fixed at one year, no matter if shelfed or used
–
this is due to the nature
of galvanic cells, in which the chemical reaction goes on at all times as long as oxygen is present.
When lifetime is over, the SmartSensor must be replaced against a fresh, readily calibrated one.
User Interface
When a low oxygen condition is encountered, the measuring station will issue an alarm, involving the built in alarm
buzzer, the red alarm lamp, and the alarm relay. The low oxygen condition will be reflected by the yellow "500" and
"1000" ppm lamps flashing.
In case of a high oxygen condition, the same applies, except that the "1500" and "2000" ppm lamps
will flash.
On the SF6 NETWORK CONTROLLER P2NC, the O2 status will be marked as "OK", "HI", or "LO",
respectively, for each measuring station.
Safety
Should the O2 sensor fail, be missing or spent, a low oxygen alarm will be issued.
