Emerson Rosemount 1199, Reference Manual, Page: 76 / 104

4.1.2 Zero-based lower range value
Figure 4-2: Remote Capillary and Direct Mount
Remote capillary Direct mount
ATM = open to atmosphere
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) – (0 in. × 0.75) = 81 inH
2
O
4 mA = L
min
× SG
P
+ d
H
× SG
F
= (0 in.
×
0.75) + (0 in.
×
0.934) = 0 inH
2
O
20 mA = L
max
×
SG
P
+ d
H
×
SGF
= (108 in. × 0.75) + (0 in. × 0.934) = 81 inH
2
O
Span = 81 inH
2
O (81 to 0 inH
2
O)
Note
Both installations would have the same calculated range points.
Note
Silicone 200 has a specific gravity of 0.934.
Configuration Reference Manual
May 2020 00809-0100-4002
76 Rosemount DP Level