Propagation Factor - Siemens SITRANS L Application Examples

Propagation factor

The path of the signal in a pipe is not direct because it interacts with the internal pipe
walls resulting in a longer path for the radar signal. To compensate, the distance
calculation must use a speed factor that is slower than the speed of light. This
propagation speed factor is dependent upon the pipe diameter and the frequency used.
Refer to the device instruction manual for a table that lists the necessary propagation
factors according to the various pipe diameters.
Propagation factor values for various pipe diameters
5.8 GHz
25 GHz
10
40 mm 50 mm
0.7953
0.9844 0.988
80 mm 100 mm
0.9254 0.9530
0.9935 0.9965
Using SITRANS LR in a Stilling Well
Application examples, 04/2020, AG070814
6
150 mm 200 mm
0.9794 0.9884