Emerson Rosemount 2140, Reference Manual, Page: 60 / 144

50
Reference Manual
00809-0100-4140, Rev AA
Hardware Installation
January 2017
Hardware Installation
Application limits

Check for risk of process medium build-up on the level switch forks.
Avoid situations where a drying and coating process medium may create an
excessive build-up (see
Figure 3-3 on page 51 ) or implement preventative
maintenance programs to ensure the build-up is not enough to impair
performance.

Ensure there is no risk of ‘bridging’ the level switch forks. Examples of products that
can create ‘bridging’ of forks are dense paper slurries and bitumen.

Problems may occur if product coats and dries causing caking.

Ensure the process is operating within the instrument operating temperature and
pressure ranges (see
“Specifications” on page 103 ).

Ensure the liquid viscosity is within the recommended viscosity range
(see
“Specifications” on page 103 ).

Check that the liquid density is higher than 0.4 SG (400 kg/m
3
)
(see “Specifications” on page 103 ).

Liquid density affects the switch-point e.g. dry-to-wet (see Figure 3-2 on page 50 ).

The Rosemount 2140 and 2140:SIS are normally insensitive to foams (i.e. they do
not see the foam). However, on rare occasions, some very dense foams may be
seen as liquid; known examples of this are found in ice-cream and orange juice
manufacturing.
Figure 3-2. Level Detection Switching Point
SP: Switching point (H
2
0)
HY: Switching point hysteresis
SP
HY
SP
0.1 in.
(2.5 mm)
0.5 in.
(13 mm)
0.5 in.
(13 mm)