Vigilantplant TDLS8000, User Manual

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<9. Inspection and Maintenance>
9-2
IM 11Y01D01-01EN
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LU and SCU optical axis misalignment
With a duct or flue with thin and easily bent walls, optical axis misalignment will occur between
the LU and SCU after the TDLS8000 is installed, degrading transmission. Refer to “3.1.2
Constructing Process Flanges”, and check the construction of the installation location. Also, in
applications that measure the gas concentration in high temperature gas, bending caused by
heat during processing may cause the optical axis to become misaligned. If this happens, refer to
“3.3 Optical Axis Adjustment”, and readjust the optical axis to the correct alignment.
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Optical axis adjustment of the LU and SCU after removing alignment flanges
If you remove alignment flanges to perform inspection and maintenance, be sure to perform
optical axis adjustment according to “3. Installation, Wiring, Optical Axis Adjustment, and Piping”
and “3.3 Optical Axis Adjustment” when you reinstall the LU and SCU in the measurement
location.
9.1.1 Transmission Calibration
After reinstalling the TDLS8000 in the measurement location and performing optical axis
adjustment according to “3.3 Optical Axis Adjustment”, perform transmission calibration.
NOTE
Optimum transmission may not be attainable if the optical axis is not adjusted correctly. Refer to
“3.3 Optical Axis Adjustment”, and perform optical axis adjustment correctly.
Execution menu path:
[HART] “Diagnosis/Service>>Transmission adjust>>Transmission adjust”
[YH8000] “ >>Execution>>Transmission Adjustment>>Measurement>>Transmission
Adjustment”
9.1.2 Process Window Cleaning
Under normal operation, if process window purge is performed correctly, the surface of the
process window rarely become stained. However, the surface of the process window may
become stained or clouded under the following conditions.
• If the gas to be measured including dust or stain makes contact with the process window
due to insufficient process window purge flow rate or purge gas pressure.
• If the surface of the process window condenses when the process window is hot
• If gas that would cause quality deterioration in the process window (e.g., hydrogen fluoride
on BK-7) makes contact with the window
• If particles, oil, and the like from the purge gas facility adheres to the surface of the process
window
If the surface of the process window is stained, remove and clean the process window according
to the following procedure.
CAUTION
Before removing the process window, check that the process is completely stopped or that the
process is isolated from open air and no process gas will be discharged.
3rd Edition: Jun. 10, 2016-00