42/24-10 EN Rev. 9
Chapter 10: Status Messages, Troubleshooting
10-21
Limas11 Problems
Temperature Problem
Faulty temperature
sensor or heater
connections
•
Check the connecting lines and plugs.
•
Check the line seating in the insulated jackets.
Defective thermal link
•
Check thermal link continuity and replace if necessary (see page 9-9 for
instructions).
Unstable Readings
Gas path leakage
•
Check the integrity of the analyzer module gas paths and (if applicable) of the
lines to the gas module (see page 9-2 for instructions).
Emitter intensity too
low
•
Read the current intensity value using the
Diagnostics/Test
→
Module
specific
→
Lamp Intensity
menu item (start the zero gas supply for this)
and compare this value to the Init value displayed (the Init values were stored
following amplification optimization after installation of a new lamp). A significant
decrease (by a factor of 10 or more) is the probable cause of unstable
measurement value readings. Three different cases can be identified:
1 If only the measurement receiver values have dropped the sample cell is
probably contaminated. Clean the sample cell (see pages 9-10, 9-12 or 9-15 for
instructions).
2 If all four values are have dropped by similar amounts then lamp intensity has
probably decreased. Perform an amplification optimization (see page 9-23 for
instructions) or replace the lamp (see page 9-21 for instructions).
3 For NO measurement only: If the reference receiver “Reference” value has
increased or not as markedly decreased as a percentage relative to the
reference receiver “Measurement” value and if at the same time the sensitivity
span has decreased (loss of sensitivity), aging of the selectivity cell is the
probable cause (see the service manual for more information).
“Sample Value Overflow or Underflow” Status Signal
Drift or aging of
optical elements
(lamp, sample cell,
detector, etc.)
•
Determine the cause
•
Clean or replace the affected elements.
•
Perform an amplification optimization (see page 9-23 for instructions) to bring
the receiver signal back to its optimal range.
