mobilephones

[deleted-24938]

what are the safety precautions i need to consider when i conduct my experiment using a mobile phone. I am ivestigating what materials stop or interfere with the receiving of a phonecall to my mobile phone. i will be testing materials such as foil, copper cloth and paper. i will be graphing the level of signal i can see on my phone

[deleted-24938]

help urgently needed

what are the safety precautions i need to consider when i conduct my experiment using a mobile phone. I am ivestigating what materials stop or interfere with the receiving of a phonecall to my mobile phone. i will be testing materials such as foil, copper cloth and paper. i will be graphing the level of signal i can see on my phone

[deleted-71447]

Hi Mould,
Thanks for your patience. These forums are designed for long term assistance, so it's not always possible to get an immediate response.

If you are using a regular cell phone under regular operating conditions, I am not aware of any special safety issues that you would need to consider related to the use of the phone. If you would like additional advice about other safety aspects of your experiements (e.g. cutting materials?) then we would need to see a detailed written procedure for your experiment.

I hope that helps,
Chris

[deleted-24938]

Hi again
Why does metal such as copper & foil interfere with the signal of a mobile phone? Is it simply because metals reflect radiowaves?
Thanks for your help
Mould

[deleted-71588]

Try putting "What is a Faraday Cage?" into answers.com. The transmission, reception, reflection, attenuation properties of materials with respect to Electromagnetic Waves is a complex subject. Michael Faraday was one of the early scientific investigators that provided some initial insight into this.

[deleted-71760]

Hi Mould,

Also, run a search (google) on "wave reflection" and "wave refraction". There are a lot of good information on how waves react when an obstacle is in their path. I hope this helps.

- James

[deleted-71588]

CAUTION: A lot of the material on general "wave reflection" and "wave refraction" interactions do not apply to the way Electro Magnetic Waves and Fields behave at conductive surfaces without taking into consideration the wavelengths. The E&M waves/fields will induce electric fields / currents on conductive surfaces which then in turn induce E&M fields and waves which then interact with the original E&M waves/fields. Analsis of these complex interactions is complicated by some orthogonal relationships between the E&M vectors and doesn't follow traditional reflection and refraction properties of sound and light waves.

A good example of this is "screen rooms" made out of 1/4 inch "hardware cloth" Light and sound waves will go right through the screen without a significant change. E&M fields at wavelengths much smaller than 1/4 of an inch will "see" this screen as a dipole antena grid and have a very complex interaction with it. E&M fields at wavelengths much larger than 1/4 of an inch will "see" this screen as a "Faraday Cage" and not pass through it.

[deleted-24938]

thanks everyone for your help. I am sure I will be in contacy soon when I start to write up my investigation
Thanks again
mould