Sprint Intros Intrinsically Safe Phone
Replying to: It's amazing by Tofuchong
Re: It's amazing
An IS device has to be effectivley sealed so that a combustible mixture can't enter the body of the phone, thus igniting during internal switching, etc. Also, you'll never see an IS device that has a conductive metal exterior (a la iPhone), unless it also has a permanent grounding conductor tied to the conductive case.
It's highly unlikely that sparks emanate from a cell-phone, unless the Li-ion battery is in process of a thermal runaway, or one is plugging or unplugging the charging cable. By far the most likely source of sparks one might see "coming from a cell-phone" is run-of-the-mill electrostatic discharge (ESD). ESD is dangerous under many circumstances, yes, but far more typically the cause is dry, windy atmospheric conditions, or static generated by one's clothing, or petting the cat or dog when the humidity is low, etc., and the phone happens to act as a grounding point. Certainly if a person's clothing, or car seat fabric, or dry atmospheric conditions have allowed a static-electricity charge to build up and one reaches for their polished aluminum iPhone, for example, one might feel or see a spark, but it's not as likely the spark was generated internally BY the cell-phone ITSELF. Possible, certainly, but normally unlikely.
IS devices are necessarily bulkier & more expensive because of the sealing required, plus the attention to detail in the internal design & choice of components, something that most customers will not put up with unless their lives depend on it. Then an extra $500 or $1000 is cheap insurance...if you will it's simply one factor in the cost of doing business in a potentially explosive atmosphere.