Oldham MX 2100, Operating And Maintenance Manual

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7.2 Fault alarms
Faults can be classified into two categories:
•
Faults concerning cells: out of range, worn cell, request for calibration in case of a major deviation during
auto-adjustment. These faults generate individual messages displayed on the relevant quadrant of the
display unit, a visual alarm and a continuous audio alarm.
•
Faults concerning the appliance itself (discharged batteries or electronic fault). The corresponding fault
message appears at the bottom of the display unit. It takes priority over all other messages concerning the
cells.
Examples of information which may be brought to the user's attention
v
"Flat batteries"
•
The batteries must be charged.
•
The remaining autonomy is about 20 minutes after which the appliance will automatically shut down.
This alarm cannot be acknowledged, only the audio signal can be cancelled.
v
" > 100% LEL: outside range"
•
This concerns only the explosimetric channel.
•
In this case:
-
The display in the quadrant concerned is frozen,
-
it is impossible to acknowledge the continuous audio signal,
-
the general alarm indicator lights come on in steady mode.
•
Normal operating conditions can be restored by stopping and restarting the MX 2100.
•
Caution must be exercised in the area owing to the presence of explosive gases exceeding LEL.
v
"Outside range"
•
Scale exceeded by 20% in negative direction, with display of negative.
•
Scale exceeded by 120% for toxic gas and oxygen.
v
"New calibration"
•
Automatic adjustment of the zero is impossible owing to, for example, excessive deviation of the zero on
the cell.
•
Replace the cell concerned.
7.3 Acknowledging alarms
7.3.1. Acknowledging gas alarms
This does not cancel the gas alarm but only the fast audio signal. When the "Acknowledge" key is pressed:
The fast audio alarm is stopped but the alarm indicator light continues flashing until the measurement is lower than the
programmed alarm threshold. The visual signal is automatically extinguished as soon as the measurement returns within
the defined limits.
A function automatically resetting the audio alarms after a given time if presence of gas persists is available on option.