Servomex 07931001B, Руководство оператора

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07931001B revision 6 © Servomex Group Limited. 2020
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6.12 In-situ validation (in-line gas validation)
Process Overview
The Laser 3 Plus includes the ability to perform in-line gas validation. This allows the
operator to check that the Laser 3 Plus is correctly measuring the target gas while
the unit remains mounted on the live process.
The in-line validation process requires that a validation cell is mounted coaxially at
the receiver end of the Laser 3 Plus. It must be possible to flow zero and span-
gases into this validation cell.
During in-line validation, the effects of the process measurement are mathematically
removed so that the Laser 3 Plus just measures the contents of the validation cell.
The cell is filled with zero-gas and then span-gas. The Laser 3 Plus checks that the
zero and span measurements are correct according to a set of user controllable
parameters. The validation cell is then purged with zero-gas before the Laser 3 Plus
returns to normal operation and the process measurement is restored.
In-line validation is a manual process that is initiated by the operator on the user
interface. The UI then transitions through a sequence of steps to perform in-line
validation. At each stage the operator is told what is happening and is given
instructions for when to turn the zero and span-gases on and off.
At the end of in-line the validation, the test result is recorded in the calibration
history.
Set up
To allow validation checks of the Laser 3 Plus analyzer when attached to the
process, the optional validation cell must be fitted at the receiver end of the
analyzer. Suitable O-ring and sealing materials must be specified for the specific
application gasses.
The pressure in the In-line validation cell must not exceed 1.5 bar
absolute.
Before using the in-line validation cell, ensure all connections are leak
free at operating pressure.
Validation gases are potentially toxic, corrosive, flammable or
asphyxiant; ensure adequate ventilation is provided.
In-line validation gases used must be well below the LEL of the gas
(<25%) and be in an inert balance gas such as N2.
The in-line validation cell volume must not form a Zoned area.