You are to specify an orifice meter for measuring the flow rate of a $35^{\circ} \mathrm{API}$ distillate $(\mathrm{SG}=0.85$ ) flowing in a $2 \mathrm{in}$. sch 160 pipe at $70^{\circ} \mathrm{F}$. The maximum flow rate expected is $2000 \mathrm{gph}$, and the available instrumentation for a differential pressure measurement has a limit of $2 \mathrm{psi}$. What size hole should the orifice plate have?