<8 TROUBLESHOOTING> 8-3
IM 11Y01B02-01E-A 3rd Edition June 19, 2012-00
•
Record Results.
Download data files from the analyzer for e-mail to Yokogawa Laser Analysis
Division.
8.1.2 Trouble Shooting Procedure for Lost and/or Low Transmission
For a TDL analyzer to function correctly there must be a suitable amount of the laser light reaching
the detector. There are several factors (or combinations of) that can affect the amount of light that is
detected on a flow cell of TDLS220:
•
Alignment:
The mechanical alignment of the laser beam with the detector unit
o
The beam is not directed at the mirror and not reflected to the detector
o
The detector not aligned with the incoming laser beam (from the mirror)
•
Contamination of Window and/or Mirror:
The process gas or other contaminants have fouled the cell window and/or mirror – cleaning
required and improvements to sample system to prevent repeat incident.
•
Particulate:
The process gas optical clarity
o
Excessive smoke density/opacity and/or particulate matter that prevents sufficient light
from reaching the detector. Improvements to the sample handling/conditioning system should
be made to remove particulate
•
Weak Laser:
The output power of the laser module itself
o
Weak or dead laser diode source not outputting sufficient light
8.2 Analyzer Warnings
Warning
Action Steps
Detector Signal Low. This is based on the amount of signal gener-
ated by the detector.
Refer to Low or Lost Transmission procedure
Transmission Low. This is the most important diagnostic feature
of the analyzer. Transmission is a measurement of the laser power
striking the detector. It is an arbitrary number (%) that can be cali-
brated. The analyzer with a clean sample flow cell is calibrated at
100% transmission when leaving the factory.
Clean window and/or mirror Refer to Low or Lost Trans-
mission procedure
Spectrum Noise High. This is based on a measurement of the
noise (standard deviation) of the absorption peak baseline regions.
Clean window and/or mirror Contact Yokogawa if fault
cannot be cleared
Process Pressure out of range. The gas pressure range for the
application is programmed into the analyzer.
Check pressure transducer feed to analyzer Check to
ensure software setting (Advanced Menu, Configure) is
correct
