What is SAR?
SAR stands for Specific Absorption Rate, and is a measure of the rate at which energy is absorbed by the human body when exposed to a radio frequency (RF) electromagnetic field. It is usually expressed in watts per kilogram (W/kg) of body mass. SAR is an important safety parameter for wireless devices such as mobile phones, as it indicates the level of RF radiation exposure to users.
How are SAR Values Calculated?
SAR values are determined through laboratory testing using a simulated model of the human body. The model is composed of materials that have properties that are similar to those of the human body. During the testing, the RF radiation is directed at the model, and the SAR value is calculated based on the amount of energy that is absorbed. The SAR value is then compared to the safety limits set by regulatory authorities to determine whether the device is safe for use.
What are the Different Types of SAR?
There are two main types of SAR: Average SAR and Peak SAR. Average SAR is the average amount of energy absorbed by the body over an entire exposure period, such as an hour or a day. Peak SAR is the maximum amount of energy absorbed by the body in a single exposure.
What are the Safety Limits for SAR Values?
Safety limits for SAR values vary from country to country. In the United States, the Federal Communications Commission (FCC) has set the SAR limit for mobile phones at 1.6 W/kg. In Europe, the limit is set at 2 W/kg, while in Japan it is set at 0.8 W/kg.
Examples of SAR Values
The following are examples of SAR values for various models of mobile phones:
- Apple iPhone 11 Pro Max: 1.22 W/kg
- Samsung Galaxy S20 Ultra: 1.47 W/kg
- Motorola Moto G Power: 1.45 W/kg
- Google Pixel 4 XL: 1.56 W/kg
It is important to note that the SAR values listed above are only examples, and actual values may vary depending on the device model and manufacturer.
Conclusion
SAR is an important safety parameter for wireless devices, as it indicates the level of RF radiation exposure to users. Safety limits for SAR values vary from country to country, and it is important to ensure that the device you are using has a SAR value that is within the limit set by your local regulatory body.
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