Hello Rick, Water departments have a rather simple device used to precisely locate leaks before digging up a street. I think they also call it a geo-phone. It worked very well the only time that I used one. Configuration was like a giant stethoscope. Didn't appear to have any electronics. Bob >Rick, > >I'm not sure if a geophone would be good for this type of thing, >maybe....I'm CCing the PSN mailing list. Maybe someone on the list has some >ideas for you. > >PSN'ers, please CC Rick at seadog@....... since he is not on the list. > >-Larry Cochrane >Redwood City, PSN > > >----- Original Message ----- >From: "Rick Howard"
>To: >Sent: Sunday, August 12, 2001 12:43 AM >Subject: geophone for urban search work > > >> Larry, >> >> Please advise whether you feel a geophone like the Mark >> Products L10B you have for sale might prove useful as >> a device to detect a person tapping on a collapsed structure >> when buried under rubble. >> >> I'm a Technical Search Specialist for one of the FEMA >> Urban Search & Rescue Task Forces, and we use a >> sophisticated device (http://www.delsar.com) as a person >> locator, but this equipment is expensive and limited as >> far as access for training. How might a geophone work as >> as a detector if someone was tapping on a structure (pipe, >> concrete, etc) 20-100 feet away? The general frequency >> range the Delsar unit calls for is 1-3000 Hz. I'd love >> to buy a geophone to experiment with. I can solder circuits >> pretty well, if you can recommend a circuit to go with it. >> >> Any advice would be appreciated. I serve in search and >> rescue as a volunteer; you'll incur no liability in >> giving me your recommendation - I'm just looking to >> experiment with other available, cheaper tools in a >> quest to do my search job better. >> >> Thanks - >> >> Rick Howard >> Tech Search Specialist >> California Task Force 3, Menlo Park ----- earthquake WARNING research ----- --- animals, people, scientific evidence --- --- http://www.earthquakewarning.org --- __________________________________________________________ Public Seismic Network Mailing List (PSN-L)
Larry Cochrane <cochrane@..............>