In open tank applications, the level can be measured with either gauge or differential pressure (DP) transmitters, using the assumption that P = LS. If specific gravity needs to be measured, then the equation can be modified to S = L/P. For this to work, the level must stay constant so that any pressure changes reflect the specific gravity change. This works well in a tank where there is no change in level, such as when it is desirable to measure a density change as a way of monitoring a reaction, or as the fluid’s temperature changes.This calculation tool only used for constant level application.

### Density Measurement for Open Tank

Density Measurement using DP transmitter for open tank for constant level application |

**The formulas for calculating the tranmitter LRV and URV are;**

**HP Side/LRV/4ma = LSmin**

**LP Side/URV/20ma = LSmax**