INSTALLATION
SETUP AND PHYSICAL INSTALLATION
WBPEEUI110505A0
3 - 9
2. Leave the low pressure
(–) connection of the transmitter
open to the atmosphere.
NOTE: It is not unheard of for bees, wasps, spiders, and other
unwanted pests to make a home of the open low pressure process
connection. To prevent this, cover this connection with a fine screen
or cheese cloth.
3. The output of the transmitter is proportional to the level of
the liquid above the cell multiplied by the specific gravity of the
liquid. If the zero point of the desired level range is above the
cell, the primary lower range value must be changed to reflect
this. Refer to
and
for more information.
for a graphical representation of this
application.
CLOSED TANK LEVEL MEASUREMENT
In a closed vessel, pressure above the liquid affects the pres-
sure measured at the bottom of the vessel. It then becomes
necessary to subtract the pressure above the liquid from the
pressure at the bottom of the vessel. Instead of leaving the
low pressure
(–) connection open to the atmosphere (as in
Figure 3-6. Closed Tank (Condensing Atmosphere) Level
Measurement
T 0 2 2 3 4 A
H IG H E S T L E V E L
TO B E M E A S U R E D
LO W E S T LE V E L
TO B E M E A S U R E D
P LU G G E D
F ILL IN G T E E
C O N D E N S AT E
P O T
W E T LE G
+
–
h
1
h
2
S G
2
S G
1
20
15
10
5
0
-2 50
(-62 .2)
D IF F E R E N T IA L P R E S S U R E
IN . H O (kPa )
2
+ 25 0
(+ 6 2.2)
4
h x S G
2
2
Z E R O
E LE VAT IO N
= h x S G
1
1
(VA R IA B L E )
h
3
O U T P U T
IN m A
Содержание Platinum standard Series
Страница 1: ......
