Siemens SITRANS LR250 Instruction Manual page 21

Propagation Factor
See
Ensure there is a vent at the upper end of the side pipe to equalize pressure and keep the
liquid-level in the pipe constant with the liquid-level in the vessel.
Mounting: Horn with Extension
GRAPHIC TO BE UPDATED
7ML19985JE01
on page 66 for the related propagation factor.
SITRANS LR250 (HART) – INSTRUCTION MANUAL
Use this combination if the nozzle is long and
the diameter is small.
A 100 mm (4") horn extension is available.
Page 17