Specifications and Reference Data
May 2016
Reference Manual
00809-0100-4530, Rev DD
224
Specifications and Reference Data
A.1.15 Interface measurements
The Rosemount 5302 is a good choice for measuring the
interface of oil and water, or other liquids with significant
dielectric differences. It is also possible to measure
interfaces with a Rosemount 5301 in applications where
the probe is fully submerged in the liquid.
If interface is to be measured, follow these criteria:
The dielectric constant of the upper product should be
known and should not vary. The Radar Master software
has a built-in dielectric constant calculator to help the
user estimate the upper product dielectric constant.
The dielectric constant of the upper product must have a
smaller dielectric constant than the lower product.
The difference between the dielectric constants for the
two products must be larger than 6.
The maximum dielectric constant for the upper product
is 7 for the single lead probes, 10 for the coaxial, and 8 for
the twin lead probes.
The upper product thickness must be larger than 5.1 in.
(0.13 m) for all probes, except the HTHP coaxial probe,
which requires 8 in. (0.2 m) to distinguish echoes from
the two liquids.
Sometimes there is an emulsion layer (mix of the
products) between the two products which can affect
interface measurements. For guidelines on emulsion,
consult your local Emerson Process Management
representative.
For information on the maximum allowable product
thickness and measuring range, see
A.1.16 High pressure steam applications
Considerations
Saturated steam under high pressure can influence radar
level transmitter measurements. Rosemount 5301 with
Dynamic Vapor Compensation will automatically
compensate for this and maintain the level accuracy.
Probe type 3V (for 3- to 4-in. chambers) or 4U (for 2-in.
chambers) must be used.
Mount in a 2-, 3-, or 4-in. bypass chamber with flanges
appropriately sized for the pressure and temperature of
the application.
Dynamic Vapor Compensation requires a minimum
distance from the flange to the surface level in order to
measure the change in the vapor dielectric constant. If
the level rises within this area, the unit switches over to
static compensation, using the last known vapor
dielectric constant.
Product Level and
Interface Level
Product Level
Interface Level
Interface
Level
Rosemount
5302
Rosemount
5301
Interface Level with
submerged probe
Minimum measuring span:
12 in. (300 mm)
Level: 0%
Level: 100%
Probe Type 3V
Short reflector (option code R1):
Minimum 22 in. (560 mm)
Long reflector (option code R2):
Minimum 28 in. (710 mm)
