Operation Manual

7. Inlet and Outlet sections

The thermal measuring principle may be sensible to inlet and outlet

conditions. For this we recommend the following minimum straight inlet

and outlet sections to ensure an accurate measurement. Sensor should

be always installed upstream from obstacles like valves, filter,

reductions etc. In common the sensor should be installed as far as

possible away from any disturbances.

Note: If there is any combination of the below, the longest straight inlet

section must be maintained.

The S 421 sensor comes with its own measuring section and a straight

inlet section, nevertheless additional straight inlet sections must be

added to measuring sections to fulfill the minimum inlet requirements.

Please refer to the installation types below and select your additional inlet

section 'LA' from the table.

Note: The additional inlet sections depend on the pipe diameter. The units for

the length are in mm.

14 S 421