From what I know, too major players are involved in hole counter mfg. They come from Japan. You'll find them in every large scale expo. These tools are very reliable and can verify from 0.2 to 5.3 mm ( 8 mils to 0,200" ). They are typically precise at +/- 0.001". However, you'll have to deal with your absolute reference and the hole condition including the surface finishes. The bright side of it... it can verify up to 40 000 holes per panel in few seconds. P.S.: They can also check hole positioning in +/- 0.001" but it take more time. How it works ? It measures uninterrupted light qty, define a surface and finally calculates the diameter based on a well known equation. Regards, Michel Poulin Technical advisor / Conseiller Technique Circo Craft Co. ( Division of Viasystems Group ) 379 Brignon Granby, Quebec (Canada) J2G 8N5 Tel.: ( 514 ) 378-0193, FAX: ( 514 ) 378-5110 E-m a i l : M i c h e l . p o u l i n @ c i r c o . c o m > ---------- > From: drilbert[SMTP:[log in to unmask]] > Reply To: TechNet Mail Forum.;drilbert > Sent: Saturday, September 13, 1997 3:47 PM > To: [log in to unmask] > Subject: Re: [TECHNET] Hole counting equipment > > I am looking for information on equipment that can optically > verify/count holes after drill. Does reliable equipment exist? How > does it work? > > Drilbert > > ############################################################## > TechNet Mail List provided as a free service by IPC using LISTSERV > 1.8c > ############################################################## > To subscribe/unsubscribe, send a message to [log in to unmask] with > following text in the body: > To subscribe: SUBSCRIBE TECHNET <your full name> > To unsubscribe: SIGNOFF TECHNET > ############################################################## > Please visit IPC web site (http://www.ipc.org/html/forum.htm) for > additional information. > For the technical support contact Dmitriy Sklyar at [log in to unmask] or > 847-509-9700 ext.311 > ############################################################## > ############################################################## TechNet Mail List provided as a free service by IPC using LISTSERV 1.8c ############################################################## To subscribe/unsubscribe, send a message to [log in to unmask] with following text in the body: To subscribe: SUBSCRIBE TECHNET <your full name> To unsubscribe: SIGNOFF TECHNET ############################################################## Please visit IPC web site (http://www.ipc.org/html/forum.htm) for additional information. For the technical support contact Dmitriy Sklyar at [log in to unmask] or 847-509-9700 ext.311 ##############################################################