Orientation In A Vessel With Obstructions; Mounting On A Stillpipe Or Bypass Pipe - Siemens SITRANS LR250 Operating Instructions Manual

4.3.3

Orientation in a vessel with obstructions

Polarization reference point
For best results on a vessel with obstructions, or a stillpipe with openings, orient the front or
back of the device toward the obstructions. For an illustration, see Device orientation (Page 32).
①
②
③
4.3.4

Mounting on a Stillpipe or Bypass Pipe

A stillpipe or bypass pipe is used for products with a low dK, or when vortex or extremely
turbulent conditions exist. It can also be used to provide optimum signal conditions on foaming
materials. See Dielectric constant of material measured in Performance (Page 185) for more
information.
● The pipe diameter must be matched with the antenna size. Use the largest antenna size that
will fit the stillpipe/bypass pipe
EN 1092-1 (Page 230), Flanged encapsulated dimensions (Page 204)or Hygienic
encapsulated dimensions (Page 208).
● One continuous length of metallic pipe is preferred, without joints.
● Any false reflections created by joints/welds/imperfections will lead to inaccuracies of the
measurement.
● Joints (if unavoidable) must be machined to ± 0.25 mm (± 0.010") and must have welded
connecting sleeve on the outside.
● If using any hygienic process connections in conjunction with a stillpipe/bypass, please
ensure that the antenna/lens are cleanable in accordance with the applicable approval.
Mounting in a pipe greater than 100 mm (4") can cause large errors, and therefore is not
1)
recommended.
Suitable pipe diameters:
SITRANS LR250 (mA/HART)
Operating Instructions, 12/2015, A5E32220602-AD
Polarization axis
Polarization reference point
Display
. See Threaded Horn dimensions, Raised-Face Flange per
1)
Horn antenna
PVDF antenna
Flanged encapsulated antenna
Installing/mounting
4.3 Proper mounting
40 to 100 mm (1.5 to 4")
50 mm (2") only
50 to 100 mm (2 to 4")
31