Specific Absorption Rate (SAR)

  Precautionary Guidelines for mobile users :

Mobile users are advised to take precautionary measures while using a mobile handset as:

1. Keep distance – Hold the cell phone away from body to the extent possible.

2. Use a headset (wired or Bluetooth) to keep the handset away from your head.

3. Do not press the phone handset against your head. Radio Frequency (RF)energy is inversely proportional to the square of the distance from the source -- being very close increases energy absorption much more.

4. Limit the length of mobile calls.

5. Use text as compared to voice wherever possible.

6. Put the cell phone on speaker mode.

7. If the radio signal is weak, a mobile phone will increase its transmission power. Find a strong signal and avoid movement – Use your phone where reception is good.

8. Metal & water are good conductors of radio waves so avoid using a mobile phone while wearing metal-framed glasses or having wet hair.

9. Let the call connect before putting the handset on your ear or start speaking and listening – A mobile phone first makes the communication at higher power and then reduces power to an adequate level. More power is radiated during call connecting time.

10. If you have a choice, use a landline (wired) phone, not a mobile phone.

11. When your phone is ON, don't carry it in chest/breast or pants pocket.
When a mobile phone is ON, it automatically transmits at high power every one or two minutes to check (poll) the network.

12. Reduce mobile phone use by children as a younger person will likely have a longer lifetime exposure to radiation from cell phones.

13.People having active medical implants should preferably keep the cell phone at least 15 cm away from the implant.

While Purchasing a Mobile Handset check the SAR value of the mobile phone. It can be searched on internet if its model number & make is known.


Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed by the body when exposed to a radio frequency (RF) electromagnetic field; although, it can also refer to absorption of other forms of energy by tissue, including ultrasound. It is defined as the power absorbed per mass of tissue and has units of watts per kilogram (W/kg). SAR is usually averaged either over the whole body, or over a small sample volume (typically 1 g or 10 g of tissue). The value cited is then the maximum level measured in the body part studied over the stated volume or mass.

SAR measures exposure to fields between 100 kHz and 10 GHz. It is commonly used to measure power absorbed from mobile phones and during MRI scans. The value will depend heavily on the geometry of the part of the body that is exposed to the RF energy, and on the exact location and geometry of the RF source.

Thus tests must be made with each specific source, such as a mobile phone model, and at the intended position of use. For example, when measuring the SAR due to a mobile phone the phone is placed at the head in a talk position. The SAR value is then measured at the location that has the highest absorption rate in the entire head, which in the case of a mobile phone is often as close to the phone's antenna as possible.

Various governments have defined safety limits for exposure to RF energy produced by mobile devices that mainly exposes the head or a limb for the RF energy:

   
  United States: The FCC requires that phones sold have a SAR level at or below 1.6 watts per kilogram (W/kg) taken over a volume containing a mass of 1 gram of tissue.
   

  European Union: CENELEC specify SAR limits within the EU, following IEC standards. For mobile phones, and other such hand-held devices, the SAR limit is 2 W/kg averaged over 10 g of tissue (IEC 62209-1).

  INDIA : India now has adopted the most stringent FCC norms for mobile handsets.

1.  All the new design of mobile handsets shall comply with the SAR values of 1.6 W/kg averaged over 1 gram of human tissue w.e.f. 1st Sept. 2012.

2.  The mobile handsets with existing designs which are compliant with 2.0 W/kg averaged over 10 gram of human tissue, continue to co-exist up to 31st August 2013.

From 1st Sept. 2013, only the mobile handsets with revised SAR value of 1.6 W/kg would be permitted to be manufactured or imported in India.

SAR value information display on the mobile handsets like IMEI (International Mobile Equipment Identity) display. The information on SAR values to be made available to the consumer at the point of sale.