Subject: Time:10:23 AM OFFICE MEMO None Date:9/26/95 Jim Marsico asked: Can anyone tell me the correlation between micrograms/square centimeter and resistivity for PWB cleanliness? Look in IPC-TM-650, 2.3.26.1, Ionizable Detection of Surface Contamination (Static Method). This test method shows the formula for the relationship between solution resistivity (starting and ending) and micrograms/sq. in. The formula is also in our Omegameter 600SMD owners manual. Mary Davis [log in to unmask]