Emerson Process Management 5300 manual Dielectric Constant Settings, Static Vapor Compensation

Rosemount 5300 Series

Reference Manual

00809-0100-4530, Rev BA July 2009

DIELECTRIC CONSTANT

SETTINGS

Static Vapor

Compensation

Figure C-11. Dielectric constants can be adjusted in the Tank Environment window.

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.

Vapor Dielectric Constant

Lower Product Dielectric

Constant

Lower Product

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.

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 7-8for further information.

C-14