Instruction Manual
D200124X012
2500 and 2503 Controllers/Transmitters
June 2017
16
Set the PROPORTIONAL BAND control on a 2500 or 2500S controller, or the SPECIFIC GRAVITY control on a 2500T
transmitter, as follows:
D
Sensor with Both Standard Torque Tube and Standard Volume Displacer
—If the torque tube is standard and the
displacer volume is close to that listed in table 2, use figure 11 to find the PROPORTIONAL BAND or SPECIFIC
GRAVITY setting. Locate the specific gravity of the process fluid on fluid level applications, or the difference
between minimum and maximum specific gravity on interface level or density applications, on the vertical axis of
the chart. From this location, trace horizontally to the curve with the desired percentage of displacer used, then
trace vertically up or down to determine the proper dial setting on the horizontal axis.
Figure 11. Proportional Band and Specific Gravity Setting Chart (chart assumes standard wall torque tube and
displacer volume in table 2)
NOTE:
EACH CURVE MARKED WITH PERCENTAGE OF DISPLACER USED.
1C9259-G
A3891-1
TRANSMITTER SPECIFIC GRAVITY SETTING
CONTROLLER PROPORTIONAL BAND SETTING
SPECIFIC GRAVITY OR SPECIFIC GRAVITY DIFFERENTIAL
D
Sensor with Nonstandard Torque Tube and/or Displacer with Other than Standard Volume
—If the construction does
not have a standard wall torque tube or has a displacer volume that deviates significantly from the volume listed in
table 2, or both, the PROPORTIONAL BAND or SPECIFIC GRAVITY dial setting does not necessarily indicate the actual
proportional band or specific gravity. To determine the correct dial setting, solve the following equation:
Corrected
DialSetting
Required
+
( L
100
)(SPGR)
ǒ
V
a
V
r
Ǔ
(X)
where:
L = percentage of displacer length desired for full output pressure change (e.g., if 80% of displacer is used, L = 80)
