Siemens SITRANS SL Operating Instructions Manual page 21

Configuration
The main feature of the in-situ analytical procedure is that the physical measurement takes
place directly in the stream of process gas and directly in the actual process gas line. All
process parameters such as gas matrix, pressure, temperature, moisture, dust load, flow
velocity and mounting orientation can influence the measuring properties of the SITRANS SL
and therefore must be considered for each new application.
The standard applications listed in the ordering data for the SITRANS SL are distinguished in
that the typical process conditions are adequately well-known and documented. If you
cannot find your application among the standard applications, please contact Siemens AG.
We will be pleased to check your possible individual application of the SITRANS SL.
Figure 2-7
Purging gas flow is used to prevent contamination of the sensor optics on the process side.
Purging tubes on the sensor heads, which slightly extend into the process gas stream, define
the effective measuring path length.
See also
Technical data (Page 181)
SITRANS SL
Operating Instructions, 12/2010, A5E01132948-04
Typical cross-duct arrangement of the SITRANS SL
Description
2.5 Functional description
23