converting unsteady pressure data to soun pressure level graph
 

hi everyone.... i'm doing unsteady flow analysis.. i've monitered pressure at a point... the unsteady pressure data has to be converted into sound pressure level data.... i used this formula
spl = 10log(p'/p^2)
but this is not working..m' getting wrog graph.. kindly some one explain about the paramters p' and p....
thank you