I am working on the comparison of traditional urine sediment analysis and Sysmex UF-4000 urine particle analyzer. The analyzer reports test results in cells per microliters whilst the manual method reports in cells per high power field. Therefore I have to convert either of the units to be in the same form as the other before I can make a comparison. I tried using the general assumption that "1 HPF is equivalent to 0.45 microliters of uncentrifuged urine" but the results I got were inconsistent.