64
2- In case of dry leg
Connect the highest liquid level tapping of tank to the low pressure side of transmitter, and
the lowest liquid level tapping of tank to the high pressure side (
fl
ange side) of transmit-
ter.
Level calculation formula
LRV:
ρ
H
1
URV:
ρ
(H
1
+ h)
Span (
∆
P):
ρ
h
LRV: Low limit of measurement (0%)
URV: High limit of measurement (100%)
ρ
:
Measuring liquid density
H
1
: Liquid
level
h:
Liquid level change
Cautions on installation
• Restriction on H
1
Liquid level is not proportional to the transmitter output at some points inside the seal
diaphragm.
Therefore, H
1
should be set higher than the value shown in the table below.
• In order to prevent vibration of the transmitter body and capillary from interfering with
output, the transmitter body should be installed at a vibration-free place and the capillary
should be
fi
xed to a stable support.
• Do not shock the seal diaphragm by hitting hard object against it, for example.
• Do not apply an excessive force to the
fl
ange during connection.
• Freeze protection.
When the measuring
fl
uid is likely to freeze in the cover of the measurement chamber, the cover
needs to be warmed up with steam or a heater.
Don't exceed the previous temperature limits (measuring cell : 120°C maxi and transmitter :
85°C).
Even when the installations shut down the heat must be maintained, if not the transmitter and
impulse pipes must be drained to prevent freezing.
H
1
Max. liquid level
Min. liquid level
R
h
Stop valve
