Vigilantplant TDLS8000, User Manual

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<9. Inspection and Maintenance>
9-21
IM 11Y01D01-01EN
9.4 Offline Validation
Offline validation is a function used to verify the validity of gas concentration measurements. For
the validation process, the TDLS8000 is separated from the measurement process, and a known
check gas if fed through a calibration cell or flow cell.
Before performing a validation, you need to enter the following information in the TDLS8000.
• Pressure of the purge check gas
• Temperature of the purge check gas
• Length of the cell to be purged with check gas
• Concentration of the purge check gas
The basic procedure is shown below.
• Set known validation parameters.
• Purge the calibration cell or flow cell with check gas of known concentration.
=> The check gas concentration reading will be recorded.
=> The expected value for the “check gas” is calculated from the known parameters.
=> The expected value and the actual value are compared and validated (pass or fail).
NOTE
Validation is a procedure to check whether the TDLS8000 is operating properly. If there is an
error in reading, calibrate.
Normally in an in-situ installation, the LU and SCU are removed from the process and mounted
to a calibration cell before performing offline validation. In a flow cell or bypass installation, offline
validation can be performed without removing the LU and SCU by switching the stream from the
process gas to check gas.
9.4.1 Preparation
Follow the instructions in “9.3 Mounting on a Calibration Cell”. There are two piping methods
for offline validation.
l
Offline validation exclusive
Connect both offline validation 1 and 2 check gases. Validation 1 and 2 can be executed.
3rd Edition: Jun. 10, 2016-00