The most reliable way is to power up the circuit and listen and watch the cap blow a hole in the board and blind the test technician - or not. But seriously . . . Another way is to use automated optical inspection, which is really only appropriate for SMT parts, because it is harder to see the marks on radial tantalums. Another way is to use Genrad's Open's Express probes (or HP's test jet) on an in-circuit test fixture overclamp. These probes can actually detect the polarity of a variety of small electrolytic caps and tantalum caps. Not all values and packages of tantalums can be reliably tested. As far as I know, there is no reliable electrical test method to detect the polarity of caps in production. Jeff Finger Manufacturability Specialist Aimtronics Corporation >>> Poh Kong Hui <[log in to unmask]> 01/14 6:40 AM >>> Hi Technetters, Is there any reliable way to detect wrong orientation on Tantalum Capacitor? Thanks ################################################################ 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 ################################################################