The formulas for calculating transmitter URV and LRV are as follows:
HP Side or LRV or Transmitter 0% = Hmin.S1 + X.S2
LP Side or URV or Transmitter 100% = Hmax.S1 + X.S2
S1 = Specific gravity of tank liquid.
S2 = Specific gravity of seal liquid.
Hmin = Equivalent head of water at minimum level.
Hmax = Equivalent head of water at maximum level.
X = Distance between transmitter and tapping point.
1. The Parameters H,X can be entered in any units like mmh20, inh20 but must be same
2. If you are using direct tubing from tapping point to transmitter without filling any additional liquid (Like water) that means you are not using any special seal liquid, so S2=S1, Here Specific gravity of Process liquid only considers for both S1 & S2. Hence S1=S2.
The Following tables specifies the seal liquid constant values: