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Service and maintenance
9.1 Instrument verification
SITRANS SL
150
Operating Instructions, 12/2010, A5E01132948-04
9.1.1
Verification with the verification tube
The verification tube is intended for the oxygen version of the SITRANS SL (SITRANS SL
O
2
).
Necessary equipment
●
Verification kit
●
Sensor connecting cable
If your regular sensor connection cable cannot be removed from the installation, you
need a supplementary one.
●
A barometer
to measure the atmospheric pressure
9.1.1.1
Verification tube
①
Transmitter
④
Receiver
②
Calibration Tube
⑤
Needle valves
③
Thermometer
Figure 9-1
Verification tube setup
The verification tube is an interface between the receiver and transmitter as shown in the
previous figure. The kit comprises a metal tube with a temperature sensor and is mounted
between the transmitter tube unit (transmitter) and receiver tube unit (receiver) during
verification. Since the verification tube has no windows, the active path will be the one
between the lenses on either tube unit. There is a small volume behind the lenses on both
sides that must be filled with nitrogen during the calibration. The SITRANS SL O2 is
designed to allow a small leakage into these volumes, and during normal usage they contain
nitrogen. By following the instructions you can assure that they stay filled with nitrogen
during the whole calibration procedure.