Detcon IR-700 - Manual (Page 21)

Model IR-700
IR-700 Instruction Manual Rev. 3.1 Page 17 of 40
Assuming acceptable sensor signal change, after 1 minute the reading will auto-adjust to the programmed
AutoSpan level. During the next 30 seconds, the AutoSpan sequence checks the sensor for acceptable reading
stability. If the sensor fails the stability check, the reading is re-adjusted back to the AutoSpan level and the
cycle repeats until the stability check is passed. Up to three additional 30-second stability check periods are
allowed before the unit reports a “Stability Fault” twice and the ITM will return to normal operation, aborting
the AutoSpan sequence. The ITM will continue to report a “Stability Fault” and will not clear the fault until a
successful AutoSpan is completed.
If the sensor passes the stability check, the ITM reports a series of messages:
“AutoSpan Complete”
“Sensor Life XXX%”
“Remove Span Gas”
d) Remove the span gas and calibration adapter. The ITM will report a live reading that alternates with
“Remove Gas” message as it clears toward “0”. When the reading clears below 5 % LEL, the ITM will
display “Span Complete” and will revert to normal operation. If the sensor fails to clear to less than 5 %
LEL in less than 5 minutes, a “Clearing Fault” will be reported twice and the ITM will return to normal
operation, aborting the AutoSpan sequence. The ITM will continue to report a “Clearing Fault” and will
not clear the fault until a successful AutoSpan is completed.
NOTE 1: If the sensor fails the minimum signal change criteria, a “Range Fault” will be
declared and a “Fault Detected” message will be displayed alternately with the sensor’s current
reading. The 4-20 output will be taken to 0mA and the “Range Fault” fault bit will be set on
the Modbus output.
NOTE 2: If the sensor fails the stability criteria, a “Stability Fault” will be declared and a
“Fault Detected” message will be displayed alternately with the sensor’s current reading. The
4-20mA output will be taken to 0mA and the “Stability Fault” fault bit will be set on the
Modbus output.
NOTE 3: If the sensor fails the clearing time criteria, a “Clearing Fault” will be declared and a
“Fault Detected” message will be displayed alternately with the sensor’s current reading. The
4-20 output will be taken to 0mA and the “Clearing Fault” fault bit will be set on the Modbus
output.
3.5 Program Mode
Program Mode provides a View Sensor Status menu to check operational and configuration parameters.
Program Mode also provides for adjustment of the AutoSpan Level, Gas Factor, Gas Type and Range, and
Serial ID. Additionally, it includes the Set Sensor Gain, Restore Factory Defaults, and Signal Output Check
diagnostic functions.
The Program Mode menu items appear in the order presented below:
View Sensor Status
Set AutoSpan Level
Set Gas Type and Range
Set Gas Factor
Set Serial ID
Set Sensor Gain
Signal Output Check