Hi Gareth, Can you monitor the fringe intensity at two adjacent locations (closer than the narrowest fringe encountered)? You could then compare the phase of the two signals. David Whalley >Hello, >I'm using an interferometry technique as a method of measuring >a flat section. The problem is that as well as using a fringe counter >mechanism to tell me how many fringe movements have occurred and thus >the height variations on the section. I also need to know which way >the fringes have moved to tell me whether the section is increasing >in height or decreasing in height. The first part of the problem was >simple to solve and so i can happily count the fringe movements and >relate them to the areas of the section. However I do not know any >hardware or software which can define clearly whether the fringes are >moving left or right. > >Can you help? > >Thanks very much > >Gareth Jones >Email: [log in to unmask] > >################################################################ >TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. >For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 >################################################################ > > > ################################################################ TechNet E-Mail Forum 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's web site (http://www.ipc.org) "On-Line Services" section for additional information. For technical support contact Hugo Scaramuzza at [log in to unmask] or 847-509-9700 ext.312 ################################################################