Emerson Process Management ROSEMOUNT 5300 - Manual (Page 262)

Reference Manual
00809-0100-4530, Rev BA
July 2009
Rosemount 5300 Series
C-14
DIELECTRIC CONSTANT
SETTINGS
Static Vapor
Compensation In some applications, there is heavy vapor above the product surface having
a significant influence on the level measurement, for example, in the case of
saturated water steam under high pressure. In such cases, the vapor
dielectric can be entered to compensate for this effect.
For applications with a varying pressure and/or temperature, certain models
of the Rosemount 5300 Series have a built-in function that automatically
compensates for varying vapor dielectric constants. See “Dynamic Vapor
Compensation” on page C-15.
The default value is equal to 1 which corresponds to the dielectricity of
vacuum. Normally this value does not need to be changed since the effect on
measurement performance is very small for most vapors.
To change the Vapor Dielectric Constant:
1. Start RRM.
2. Click the Tank icon in the RRM workspace, or choose Tank from the
Setup menu.
3. Select the Environment tab and click the Advanced button.
Figure C-11. Dielectric constants
can be adjusted in the Tank
Environment window.
4. Type the desired value in the Vapor Dielectric Constant field. You may
also use the Vapor Dielectric Calculator or the Vapor Dielectric Chart to
find the correct value.
Lower Product If the dielectric constant of the lower product is significantly smaller than the
dielectric constant of water, you may need to adjust the Lower Product
Dielectric Range, see Figure C-11.
Special adjustments can also be made by trimming the appropriate amplitude
thresholds. See section “Interface Pulse not Found” on page 7-8 for further
information.
Vapor Dielectric Constant
Lower Product Dielectric
Constant