Ken How long is a piece of string? What flux are you using? What cleaning method (if any) are you using? What kind of assembly are you making? What are the climatic conditions under which it will be working? What reliability are you wanting? With all the best will in the world, it is impossible to answer your question. Contrary to the all MIL specs and other similar standards, the famous figures of 1.5 to 1.6 ug/cm2 eq. NaCl is meaningless, stupid and ridiculous. In the first place, they were derived empirically from loosely populated boards with large through-hole components, using one specific wave-soldering high-solids liquid flux and one specific cleaning process with one specific solvent. Secondly, they take no account of the conditions under which the assemblies will be used. Thirdly, do you want the same reliability for a toy as with a satellite? There is only one person who can answer your question. YOU! You manufacture, say, 20 assemblies, using a method that you know will satisfy the required reliability criteria and everything else. You measure their residual contamination. You calculate the arithmetic mean and standard deviation. That is your benchmark for ONLY that particular assembly made using ONLY that particular process. Any major and consistent change, in either direction, means that your process has gone off the rails. By "major", I mean, say, 20% or more falling outside the mean +/- 1/2 SD; the new mean changing by more than about 10% or the SD widening. In short, 0.3 ug/cm2 eq. NaCl may be insufficient for some applications and 2.5 ug.cm2 eq. NaCl may be far too tough for others. Absolute figures are meaningless, IMHO. And I say this as the original conceptor of the Contaminometer, although the same applies to ther two Alpha instruments and every other similar one. Brian Ken Patel wrote: > > Guys, > What is the acceptable Ionic contamination limit for Omegameter 600 and > Inograph 500 both made by Alphametals? > > re, > ken patel > > --------------------------------------------------------------------------------- > Technet Mail List provided as a free service by IPC using LISTSERV 1.8d > To unsubscribe, send a message to [log in to unmask] with following text in > the BODY (NOT the subject field): SIGNOFF Technet > Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional > information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 > --------------------------------------------------------------------------------- --------------------------------------------------------------------------------- Technet Mail List provided as a free service by IPC using LISTSERV 1.8d To unsubscribe, send a message to [log in to unmask] with following text in the BODY (NOT the subject field): SIGNOFF Technet Search previous postings at: www.ipc.org > On-Line Resources & Databases > E-mail Archives Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information, or contact Keach Sasamori at [log in to unmask] or 847-509-9700 ext.5315 ---------------------------------------------------------------------------------