our application is measure the tank Level using pressure sensor.then we convert the level to qty.
our problem is temperature is decrease from 20 C to 4 C pressure level is also decrease(About 10 MM ).
we used following formula for Pressure to Level conversion
L = P / (ρ x g)
ρ = ρ0 x SG
ρ0 = Density of liquid (1000)
SG = 1.033 (at 4 C)
(we used density of milk = 1.003073 - 0.000179t - 0.000368F + 0.00374N)
where t = temperature in degrees C; F = percent fat; and N = percent nonfat solids(SNF)
g = 9.80665 ms-2