The flow rate in a $1.5 \mathrm{in}$. ID line can vary from 100 to $1000 \mathrm{bbl} /$ day, and you must install an orifice meter to measure it. If you use a differential pressure (DP) cell with a range of $10 \mathrm{in}$. $\mathrm{H}_{2} \mathrm{O}$ to measure the pressure drop across the orifice, what size orifice should you use? After this orifice is installed, you find that the DP cell reads 0.5 in. $\mathrm{H}_{2} \mathrm{O}$. What is the flow rate in barrels per day (bbl/day)? The fluid in the pipe is an oil with an $\mathrm{SG}=0.89$ and $\mu=1 \mathrm{cP}$.