Given that they are radio transmitters, there is always the risk that they can cause a spark and ignite something. Additionally, reports have happened of the battery itself getting shorted when removed and causing everything from bullets to other explosive situations to occur. When you short the metal contacts on the battery it gets very hot, that heat can cause things to ignite (gasoline for example needs about 500 degrees farenheight to ignite).
Cell phones are normally upto 600mW PEP (max FCC allowed for a handheld). Wifi devices are normally upto 200mW PEP. Amplifiers can change this. ETSI in europe limits to 100mW PEP and in Japan wifi is limited to 10mW or something silly. Thus its less of a concern in other regions. If you put a little bit of metal in the microwave you will see sparks on the metal. This is because there is a difference in RF potential across two points, and an arcing occurs. Granted most microwaves are 600-1000W PEP, or 1000+ times the power, but the same type of situation can occur if conditions are right. In short there is no way to completly reduce the chance of explosions of certain substances, to get a cell phone far enough away to mitigate that danger is a matter of inches (1 inch == 2.54 cm), a wifi device, having less power, is an even shorter distance. If you are very near dangerous substances that could be set off this way you should (hopefully anyway) be trained in proper procedure there. There is more risk (I think anyway) of filling a plastic gas can inside a pickup bed with a plastic liner (plastic on plastic can create a static discharge). Cigarettes often dont get hot enough to ignite gasoline (outside movies) because only when inhaling do they near hot enough, just tossing one onto gas its normally 50 degrees below the flash point. Remember liquids dont burn, only gasses do in normal physics anyway (special conditions can occur with extreme temperatures and pressures). Gas station tanks are grounded if metal, the pumps certainly are. This further mitigates risk. AFAIK there arent regulations that require them to prevent explosions, any regulations like that would be on the devices that contain or transport such materials that are likely to explode. Because people transmit a lot of power on mobile radios, those working with detonators at construction sites often are required to put out signs saying 'dont transmit explosive danger' because you can cause a false fire signal to be sent to the detonator if you kick out enough power, but even those devices are typically shielded to minimize this risk. On Fri, 2005-06-17 at 10:49 -0400, Daryl G. Jurbala wrote: > > -----Original Message----- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of > > Anton Krall > > Sent: Wednesday, June 15, 2005 3:01 PM > > To: 'Asterisk Users Mailing List - Non-Commercial Discussion' > > Subject: [Asterisk-Users] WiFi IP Phones > > > > Guys. > > > > I know there are wifi sip phones out there but I have a > > question, are any of these phones "anti explosive"? By that I > > mean, there are certain regulations about phones or cel > > phones that are not recommended to operate in environments > > like gas stations due to sparks and the chance of ingiting gas fumes. > > You are referring to (in the US anyway) certification as "intrinsically > safe". > > I don't know either way about phones listed as such, but with the right > terminology you might have better liuck searching. > > voiceverified. | Daryl G. Jurbala > -------------- | Chief Technology Officer > | 215.862.1160 x235 (Office) > It had to be you! | 215.862.9880 (FAX) > > > _______________________________________________ > Asterisk-Users mailing list > [email protected] > http://lists.digium.com/mailman/listinfo/asterisk-users > To UNSUBSCRIBE or update options visit: > http://lists.digium.com/mailman/listinfo/asterisk-users -- Trixter http://www.0xdecafbad.com Bret McDanel UK +44 870 340 4605 Germany +49 801 777 555 3402 US +1 360 207 0479 or +1 516 687 5200 FreeWorldDialup: 635378
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