Drum Level Methods of of Compensation 1

Density Compensation for boiler drum Level Measurement 1
If the measurements are sensitive to density variation, then density compensation techniques must be employed.
For most boilers, corrections must be made for the changes in accuracy.
There are several approaches that can be taken to calibrate the dP transmitter.
The compensation block gives out put modified as per the densities of water & steam at the saturated drum pressure. So the indicator/controller shows the correct drum level.
Here it has been tried to explain pressure compensation of boiler drum level measurement. (It is also called density compensation because drum water and drum steam density changes with drum pressure.)
A system block approach has been used to explain the concepts.