Service and maintenance
9.1 Instrument verification
SITRANS SL
158
Operating Instructions, 12/2010, A5E01132948-04
Step 2: Preparations and LUI settings
In order to document the verification procedure you should fill out the 'SITRANS SL CO
Verification sheet' form thoroughly during verification.
1.
Make a copy of the "Verification sheet" form you can find in Annex A.
2.
Fill out the first part (General Information).
3.
Enter the password to access the Local User Interface (LUI) using the remote control.
NOTICE
Remember to write down the original values before making any alterations to the
settings!
4.
Note the current integration time in the verification sheet. Set the integration time to 20 s.
5.
Note the settings for the path length in the verification sheet. Set the path length to the
value stated in the certificate. Notice that this is valid with the in-line reference cell in
place.
Note this value also in the verification sheet.
6.
Note pressure source settings and, if applicable, pressure manual value in the verification
sheet. Set the pressure source to "manual" and enter the value stated in the certificate.
Note this value also in the verification sheet.
7.
Note temperature source settings and, if applicable, temperature manual value in the
verification sheet. Set the temperature source to "manual" and set the temperature
manual value to the ambient temperature.
Note this value also in the verification sheet.
8.
Enter the appropriate values for the verification errors: Instrument error (according to the
instrument specifications), and temperature error.
The temperature error depends on your measurement. If the system and the purging gas
used are well tempered, you can use the error of the thermometer itself: 1 °C.
9.
Calculate the total uncertainty of the measurement by adding instrument error, and
temperature error.
CAUTION
Temperature influence on the verification procedure
It is very important to enter the accurate temperature values. As a rule of thumb you
need the same accuracy of the temperature values you expect for your verification
tolerance.