**Density Measurement using DP transmitter for open tank with constant level application**

In open tank applications, 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 fluidâ€™s temperature changes.This calculation tool only used for constant level application.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**

Where

L = Open tank maximum measured level

Smax =Â Maximum process specific gravity

Smin = Minimum process specific gravity

Note: This calculation is only used for open tank vented and for constant level application.