User's Manual

Page 22 SITRANS LR250 (HART) – INSTRUCTION MANUAL 7ML19985JE03
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Installation
Nozzle location (continued)
• Provide easy access for viewing
the display and programming via
the hand programmer.
• Provide an environment suitable
to the housing rating and
materials of construction.
• Provide a sunshield if the
instrument will be mounted in
direct sunlight.
Orientation in a vessel with obstructions
Polarization reference point
Mounting on a Stillpipe or Bypass Pipe
A stillpipe or bypass is used for products with a low dK
1)
, or when vortex or extremely
turbulent conditions exist. It can also be used to provide optimum signal conditions on
foaming materials.
Stillpipe or Bypass Pipe requirements
• The pipe diameter must be matched with the horn size. Use the largest horn size
that will fit the stillpipe/bypass pipe (see
Threaded Horn dimensions on page 13 or
Flanged Horn dimensions on page 15).
• Suitable pipe diameters: 40 mm (1.5") to 100 mm (4”).
Not recommended: (152.4 mm/ 6" or 203.2 mm/ 8")
• One continuous length of metallic pipe is preferred, without joints
2)
.
1)
See Dielectric constant of material measured on page 8.
2)
Bad joints create reflections.
ambient temperature
–40 °C to 80 °C
(–40 °F to 176 °F)
process temperature
with FKM O-ring:
–40 to +200 °C
(–40 to +392 °F)
with FFKM O-ring:
–20 to +200 °C
(–4 to +392 °F)
polarization reference point
polarization
axis
display
For best results on a vessel with obstructions, or a stillpipe with
openings, orient the front or back of the device toward the
obstructions (see
Device orientation on page 23 for an
illustration).