Vigilantplant TDLS8000, User Manual

Page: 198 / 320

<9. Inspection and Maintenance>
9-25
IM 11Y01D01-01EN
Operator HART/HMI screen Valve1 Valve2
AO/DO
mode
[Screen operation] Start offline validation 1
OFF
OFF Normal output
[Manual valve operation] Purge with check gas
Check gas
purging
ON OFF
Cal/Val
(Wait for the gas concentration to stabilize.)
(Check validation result.)
[Screen operation] Proceed to the next step (or retry)
[Manual valve operation] Discharge check gas
Check gas
discharging
OFF OFF
(Wait for the gas concentration to stabilize.)
[Screen operation] Proceed to the next step
[Screen operation] Touch Execute
Offline validation 1
end
Validation result
Normal output
Time
Figure 9.12 Valve and AO/DO output for manual offline validation 1
Operator HART/HMI screen Valve1 Valve2
AO/DO
mode
[Screen operation] Start offline validation 2
OFF
OFF Normal output
[Manual valve operation] Purge with check gas
Check gas purging
ON ON
Cal/Val
(Wait for the gas concentration to stabilize.)
(Check validation result.)
[Screen operation] Proceed to the next step (or retry)
[Manual valve operation] Discharge check gas
Check gas
discharging
OFF OFF
(Wait for the gas concentration to stabilize.)
[Screen operation] Proceed to the next step
[Screen operation] Touch Execute
Offline validation 2
end
Validation result
Normal output
Time
Figure 9.13 Valve and AO/DO output for manual offline validation 2
9.5 Zero Calibration
Zero calibration is a function used to align the zero point in a condition where absolutely none of
the measured components are absorbed by running gas (such as nitrogen) that does not include
the measured components in the region where the laser beam passes through.
Typically zero calibration is performed in an ideal environment before product shipment. In
principle, the TDLS8000 does not have any zero point drift. Therefore, customers normally do not
have to perform zero calibration.
However, if the zero reading is clearly not normal or if you decide that zero calibration is
necessary, perform a zero calibration by paying attention to the following items.
Not meeting the following conditions may adversely affect measurement gas readings.
If you are unclear about how to perform zero calibration, contact your nearest Yokogawa
representative.
Note the following items to perform zero calibration correctly.
• Nitrogen gas concentration meeting the product specifications (99.99%N
2
or higher,
depends on the application)
3rd Edition: Jun. 10, 2016-00