Calculation and Setting D/P Level Transmitter

I have instalation level transmitter under tank (zero suppresion),close tank,dryleg.heigh of level (h)=1755mm.distance from min level to high tappoint(y)=0mm,distance from high tappoint to transmitter(z)=1000mm.sg1 liquid in tank = 0.54.sg2 liquid in impulstube =0.54.now Iwant to make range of transmitter.

span=hxsg1.( 1755mm x 0.54 = 947.7mmh2o)

zs=yxsg1 + zxsg2.( 0x0.54 + 1000x0.54 =540mmh2o)

range transmitter is 540 mmh2o to 947.7 + 540 mmh2o.(540 mmh2o to 1487.7 mmh2o).we write range -540mmh2o to 1487.7 mmh2o.for all my friend in CR4 how about this calculation,are you have another calculation.

my best regards