Emerson Rosemount 3308, Reference Manual

Page: 23 / 128

Reference Manual
00809-XXXX-4811, Rev AA
February 2012
2-11
Rosemount 3308
PRELIMINARY
PROBE SELECTION
GUIDE
Use the following guidelines to choose appropriate probe for your
Rosemount 3308 transmitter:
Table 2-1. Probe selection guide. G=Good, NR=Not Recommended, AD=Application Dependent (consult factory)
Coaxial Rigid Twin Lead Flexible Twin Lead Rigid Single Lead Flexible Single Lead
Measurements
Level G G G G G
Interface (liquid/liquid) G
(1)
G G NR NR
Process Medium Characteristics
Changing density G G G G G
Changing dielectric
(2)
G G G G G
Wide pH variations G G G G G
Pressure changes G G G G G
Temperature changes G G G G G
Condensing vapors G G G G G
Bubbling/boiling surfaces G G AD G AD
Foam (mechanical
avoidance)
AD NR NR NR NR
Foam (top of foam
measurement)
NR AD AD AD AD
Foam (foam and liquid
measurement)
NR AD AD NR NR
Clean liquids G G G G G
Liquid with dielectric<2.5 G AD AD AD
(3)
NR
Coating liquids NR NR NR AD AD
Viscous liquids NR AD AD AD G
Crystallizing liquids NR NR NR AD AD
Solids/Powders NR NR NR AD AD
Fibrous liquids NR NR NR G G
Tank Environment Considerations
Probe is close
(<12 in./30 cm) to tank wall
/ disturbing objects
G AD AD NR NR
High turbulence G G AD G AD
Turbulent conditions
causing breaking forces
NR NR AD NR AD
Long and small mounting
nozzles
(diameter <6 in./15 cm,
height>di 4 in./10
cm)
G AD NR NR NR
Probe might touch nozzle /
disturbing object
G NR NR NR NR
Liquid or vapor spray might
touch probe
G NR NR NR NR
Disturbing EMC
environment in tank
AD NR NR NR NR
(1) Not in fully immersed applications.
(2) For overall level applications a changing dielectric has no effect on the measurement. For interface measurements a changing dielectric of the top fluid
will degrade the accuracy of the interface measurement.
(3) OK when installed in pipe.