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8. Diagnostic Features
Sensor Failure
The S300, 305, 500 & 505 monitors have inbuilt diagnostics to
detect sensor faults. If the sensor fails it can be easily replaced
by simply removing and installing a new one. The failed sensor
can be sent back to Aeroqual for refurbishment or disposal.
Table of monitor status conditions
Fault
description
LCD
screen
0-5 V
output
Control
output
Low
alarm
output
High
alarm
output
Data logging
(S500 only)
No fault
Valid
gas
reading
Reading
proportional
to gas
reading
As set
by
user
As set
by
user
As set by
user
valid gas
reading
Sensor
failed fault
Sensor
failure
5 V
open
closed
closed
9999
Sensor
aging fault
Valid
gas
Reading
+
Sensor
aging
Reading
proportional
to gas
reading
As set
by
user
As set
by
user
As set by
user
valid gas
reading
Communi-
cations
failure
Unit will
turn off
0 V
open
open
open
No output
Sensor
standby
Standby
symbol
0 V
open
open
open
No output