Siemens Sitrans LR200, Быстрый старт, Страница: 7 / 276

Page EN-6 SITRANS LR200 (HART) – QUICK START MANUAL 7ML19985XC81
mmmmm
English
Nozzle design
• The end of the shield section should protrude a minimum
of 10 mm (0.4”) to avoid false echoes being reflected from
the nozzle.
Location on a manhole cover
• A manhole cover is typically a covered nozzle with a
diameter 610 mm (24”) or greater.
• For optimum signal conditions, locate the antenna
off-center, typically 100 mm (4") from the side.
Nozzle location
• Keep emission cone free of interference
from ladders, pipes, I-beams or filling
streams.
• Locate the antenna away from the side
wall, to avoid interference from indirect
echoes.
• Make allowance for the emission cone
spreading, to avoid interference with
vessel walls or obstructions.
Notes:
• For nozzles 100 mm (4") in length or shorter use the 100 mm (4") shield.
• For nozzles 250 mm (10") in length or shorter use the 250 mm (10") shield.
• For details on other applications, please see the full manual.
WARNING: For vessels with conical or parabolic tops, avoid mounting the
instrument at the centre. (The concavity of the top can focus echoes into the centre,
giving false readings.)
10 mm
(0.4")
shield
100 mm (4")
Coni
Fl at
Parabolic
Conical
undesirable
Note: Under certain circumstances, it
may be acceptable to mount the device
at the centre of a flat-topped tank.
Please discuss this with your local
Siemens representative.
Flat
preferred
min. 300 mm (1ft)
per 3 m (10’) of vessel
height
beam
angle
20
o
emission
cone