Spectrex Series 300 Open-Path Gas Detection System - Manual (Page 16)

Spectrex Inc. - SafEye TM 300 Gas Detector Manual – TM 794100, Rev. D, May 2004
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3. Operation Mode
The SafEye system has three operation modes; Normal, Alignment and Zero
Calibration.
3.1 Normal Mode
This mode is used for gas detection. The following status signals are possible:
(see Table 2 for visual indications).
Normal - Signal received from gas detection is at safe levels.
Warning - Gases have been detected at warning levels.
Alarm - Gases have been detected at alarm levels.
3.2 Fault Mode
There are three fault types:
•
Fault 1 (2mA Output) – Non critical
If this occurs, it is due to blockage, poor alignment, very low signal or in
the case of partial obscuration or full beam block and detection is no
longer possible. The Detector’s proper operation will be restored (Auto
reset) during operation if the condition causing the problem is removed or
resolved. This mode will occur after a delay of 60 sec. from the moment
of the fault. This delay is important to eliminate momentary obscuration
due to objects/people passing through the beam.
•
Low Voltage Fault (0mA Output)
In this case, detection is disabled due to low voltage being supplied to
the Detector. The Detector returns to proper operation only when proper
voltage level restored.
Fault 2 (0mA Output) – Critical
In this case, the detection is disabled due to electrical / software
operational failure or central device (memory, processor) fault. Such fault
causes the Detector to cease operation.
3.3 Alignment Mode
This mode is used when the received signal needs to be measured (i.e.
Installation & Periodic Maintena nce). LED indications represent the received
signal strength for precise alignment. There is a temporary Standby Mode to give
the option of switching from Alignment Mode to Calibration Mode.
3.4 Zero Calibration Mode (1mA Output)
This mode zeros the base level from which the Detector will read gas.
It should only be performed when there are:
•
No combustible gases present
•
Clear path between the Light Source and Detector
•
Clear weather conditions.