Silver nitrate test is to check for the presence of OSP only. To check for thickness you need to process a standard coupon, dissolve the OSP in an mild acid, and process solution sample in a UV Spectraphotometer. Then convert the reading to thickness with a correlation constant. Enthone OMI can provide you with all of the details. D. Mitchell Zycon Corp. [log in to unmask] ______________________________ Reply Separator _________________________________ Subject: OSP Questions Author: [log in to unmask] at corp Date: 1/12/96 10:38 AM Can anyone tell me where to get Data on a "Silver Nitrate Test" to check thickness on OSP's. Has anyone arrived on an acceptable thickness range on OSP's at this time? Thanks in Advance for any response Nancy Nelson PCA Eng. Services Dell Computer 512.728.0016 Fax 512.728.3653