Emerson Rosemount 3108, Быстрый старт

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4 Installation
• Mount the transmitter above the liquid using the 1-in. threaded
connection provided, but no closer than 13.8 in. (0,35 m) to the surface.
The transmitter does not detect any liquid surface closer than 12 in. (0,3
m) to the transmitter face.
• The transmitter should be mounted vertically to ensure a good echo
from the liquid surface. The beam half angle of the transmitter is 6
degrees (
Figure 4-2 ).
• Obstructions in the tank, or well, may generate echoes which can be
confused with the real liquid surface echo. Obstructions within the beam
angle generate strong false echoes. Wherever possible, the transmitter
should be positioned to avoid false echoes.
• To avoid detecting unwanted objects in the tank or well, it is advisable to
maintain a distance of at least 1.3-in (33.02 mm). from the center line of
the transmitter for every foot (11 cm per meter) range to the
obstruction. (See
Figure 4-2 ).
• No false echoes are generated if the transmitter is located near the side
of the tank or well and the wall is smooth and free of protrusions.
However, there will still be a reduction in the echo size. It is
recommended that the transmitter be mounted no closer than 12 in.
(0,3 m) to the wall to avoid a large reduction in the echo size.
• If the transmitter is mounted in an enclosed tank with a domed top,
avoid mounting the transmitter in the center of the tank roof because
this could act as a parabolic reflector and create unwanted echoes.
• Avoid applications where heavy condensation could form on the
transmitter face.
• If the transmitter is mounted in a stand-off or nozzle, the transmitter
face should protrude at least 0.2 in. (5 mm) into the tank.
• If the transmitter is used in environments where direct sunlight can
cause high surface temperatures on exposed instruments, a sun-shade is
recommended.
4.1 Mounting the transmitter above the liquid surface
A one-inch threaded process connection is provided to mount the
transmitter (
Figure 4-1 ). The thread form is either BSPP (G1) or NPT, and is
marked below the mounting thread.
Mounting bracket
The transmitter is supplied with a purpose made 316 Stainless Steel
mounting bracket (
Figure 4-1 ), which should be used to mount the
August 2019 Quick Start Guide
Quick Start Guide 11