What is interface level ? How do you calculate it?

When a vessel is filled with two liquids of two different specific gravities the level measurement refers to as interface level.

DP = H (D - d)


On a level set the difference of two specific gravities.

Calibration of Interface Level Measurement

On an interface leveltrol there are two liquid of two different specific gravities.

  1. The level will be zero when it is full of lighter liquid.

    Zero % level = H X d.

    H = Displacer length
    d = Specific gravity of lighter liquid.

2 The level will be 100 % when it is full of heavier liquid.

100 % level = H X D.

D = Specific gravity of heavier liquid.

Calibration with water:

  1. Fill H X d level with water adjust zero.
  2. Fill H X D level with water adjust Sp. gravity or span.
  3. Check linearity.

From above formulas can we analyze tank levels?