Emerson Rosemount 1199, Reference Manual

Page: 79 / 104

4.1.5 Non-zero based lower range value (Tuned-System
assembly)
Figure 4-5: Tuned-System
™
L
max
L
min
108 in.
0 in.
SG = 0.75
P
SG = 0.934
F
d = 120 in.
L
d
H
= vertical distance from transmitter to high pressure seal
d
L
= vertical distance from transmitter to low pressure seal
L
max
= the maximum level of process above the high pressure seal and typically the 20
mA lower range value
L
min
= the minimum level of process above the high pressure seal and typically the 4 mA
lower range value
SG
F
= specific gravity of fill fluid
SG
P
= specific gravity of process fluid
Tank span = L
max
× SG
P
– L
min
× SG
P
= (108 in.
×
0.75) = 81 inH
2
O
4 mA = L
min
×
SG
P
– (d
L
×
SG
F
)
= (0 in. × 0.75) – (120 in. × 0.934) = –112.08 inH
2
O
20 mA = L
max
× SG
P
– (d
L
× SG
F
)
= (108 in.
×
0.75) – (120 in.
×
0.934) = –31.08 inH
2
O
Span = 81 inH
2
O (–112.08 to –31.08 inH
2
O)
Note
Silicone 200 has a specific gravity of 0.934.
Reference Manual Configuration
00809-0100-4002 May 2020
Rosemount DP Level 79