SAR tests in the laboratory and human exposure occurs at radio frequency

SAR tests in the laboratory and human exposure occurs at radio frequency

The wireless handheld devices are now part of our daily habits and have almost become an extension of ourselves.
Frequently we use the smartphone and carry it in his pocket, or we the smartwatch the wrist and do not think that we are exposing our body parts, and hold, to electromagnetic fields generated by these objects that are always connected to some communication network.
The broadcasting apparatus usable in close contact with the body must be subjected to specific tests before being put on the market: the assessment of’human exposure to electromagnetic fields and the so-called SAR measurement.

What is the SAR?

The SAR, stands for Specific Absorption Rate It is defined as the amount of EM energy absorbed by human body tissues on unit mass and is measured in W / Kg.
The SAR testing, then, measure the percentage of electromagnetic energy absorbed by the human body when this is located in the vicinity of a magnetic field radiofrequency. The values ​​thus obtained make it possible to verify that they comply with the limits of safe exposure to electromagnetic fields.

Following the guidelines defined by 'International Committee for Non-Ionising Radiation Protection (ICNIRP), the European Union, the United States, it Canada, Japan, Australia and other, approved standards, which determine the maximum emission levels permitted to contain within certain safety thresholds tolerance absorption.
By incorporating these provisions, in the allowable SAR value of the EU is 2 W / Kg su 10 grams of tissue. The US and Canada regulations impose stricter parameters, by fixing the limit at 1,6 W / Kg misurati su 1 gram of tissue.

The SAR testing in laboratories Sicom Testing

SAR measurement system Sicom Testing It performs the SAR measurement of electrical equipment, electronic and telecommunication can be used in the vicinity of the body.
This workshop is specially equipped for measuring the specific absorption rate of electromagnetic energy by the human tissue when exposed to EMC fields.
The equipment available to Sicom Testing allow you to perform SAR measurements of small objects, such as portable phones, or larger devices.
All measurements can be applied to various sensitive parts of the human body such as the head, the abdomen or wrist.

The SAR measurement is carried out using a machine made by a robotic arm, by an electric field probe and from special tanks, the shape of which reproduces the model and of the head of the human body. Inside the tanks it is contained a special liquid that allows to simulate the characteristics of human tissue.
The device on which tests are carried out is then positioned at the bottom of the tanks so as to simulate the use in the vicinity of the head or body. The measurement is carried out by means of a complex test procedure, at the end of which the value obtained by the measures is compared with the limits laid down by the regulations rifermento.

Sicom Testing: experience, expertise and continuous innovation

Thermography of the head The lab Sicom Testing dedicated to this type of test and measurement, and realized thanks to the collaboration of the Research Area Science Park and Friuli Venezia Giulia, from the 2006 It is unique in the area and established itself nationally recognized for its expertise in the field of checks on’human exposure.
In this compound Sicom Testing He has developed proven expertise in measuring techniques, calculation and simulation for SAR measurement, verifying the conformity of various devices to the various existing standards.

The continuous evolution of the reference standard is accompanied by a constant work of renovation, focused on skills and training of personnel as well as on laboratory instrumentation.

Sicom Testing It offers a complete service for the risk assessment of human exposure to electromagnetic fields and SAR measurement of your products.

To request more information on this topic, write to info@sicomtesting.com
or call +39 0481 778931.

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50 thoughts on “SAR tests in the laboratory and human exposure occurs at radio frequency”

    • Good morning Yitzac,
      the SAR value is expressed in units of watts per kilogram (W / kg) and the manufacturer shall indicate in the user manual.
      Kind regards
      Staff Sicom

    • Good evening,
      I would like to kindly have a little information below:
      – what kind of liquid is used in the test tanks and in what sense it allows to simulate the characteristics of human tissue?
      – the value of 2 W/kg per 10g, how it relates to the other radio transmission threshold imposed (at the moment) a 6V/m?
      – remember that about the SAR parameter, there was talk of thermal related effects (in fact, you reported a color image of thermography) to raise the temperature on the skin interface in contact with a mobile phone. But there are also studies on the possible interrelation with the cells of the deeper layers and not only at a thermal level?
      I imagine that your systems also allow you to calculate SAR and effects generated by other devices in the microwave range (ovens etc.), am I right ?
      Thank you very much and see you soon
      Alberto

      • Good morning,
        – the liquid used in the test tanks simulates human tissue having the same transmission and absorption properties as the electromagnetic field;
        – the value of 2W / Kg for 10 g does not directly relate to the environmental limit of 6V / m;
        – some medical studies state that a temperature rise above 1 ° C is not negligible. However when the SAR measurement techniques were defined, the experts preferred a method based on the measurement of the electric field because it was more reliable and precise. Currently, human exposure to electromagnetic fields must be assessed for all electrical and electronic systems. The applied technique and the laboratory measurements to be carried out depend on how the equipment is used.
        In the specific case of the microwave oven, the SAR measurement is not applied.
        Greetings from Sicom Testing

  1. The SAR of a person can be "X", Due to non-ionizing radiation emissions a mobile Base Station ? In short, is a person can learn how to absorb the radiation from an antenna?

    • Hello Cristian,
      thanks for contacting us.
      The SAR measurement and evaluation of human exposure to electromagnetic fields in general have precisely the purpose of determining how much radiation absorbs the human body exposed to a specific electromagnetic field source, for example mobile phone or base station.
      Normally, the SAR value is obtained by performing the tests on a radio device in a laboratory. In the case of a base station, the evidence relating to human exposure that can be made are those of the electric fields.
      Kind regards
      Staff Sicom

    • Good afternoon. What is the difference between head and body SAR? Because the coefficients are different on a phone: for the head-0,3, for the body-1.38?

      • Good morning.
        The SAR of the head assesses human exposure when the product is used placed on the ear, as happens in traditional telephony.
        The body's SAR assesses human exposure when the product is used close to the body, for example attached to the belt, held in your pocket or in your hand.
        There are some technical differences in the two measures. For the head SAR, only one side of the product is typically facing the head, while for the body SAR the test is typically repeated on all sides of the product. The latter can be one of the causes of the difference in values ​​that are obtained.
        Greetings from Sicom Testing

  2. Salve. I lived in 60 meters from a cellphone tower 21 years. What test would show whether a human or a dog could suffer the effects of that RF radiation?

    • Hello Shelley Ellis, thanks for contacting us. It can carry out field environmental testing to verify that the RF radiation fall within the limits provided by the regulations. Usually these tests are performed by specialized technical team to produce appropriate instrumentation.
      Kind regards
      Staff Sicom

  3. Good afternoon, I want to know if the SAR of a terminal lowers wearing warm clothes (I refer to the SAR in the body). Thank you

    • Hello Natalia, thanks for contacting us. It's’ possible that the SAR level of a device is lowered if you wear clothing. In general, the SAR value depends on the distance that exists between the body and the radio-transmitting device.
      Kind regards
      Staff Sicom

  4. The SAR value is the energy generated by RF fields ? so 1.73 w / kg emitting X phone is the heat energy generated by the body RF absorbed?

    • Good morning Edgar, thanks for contacting us.
      The SAR value expresses the measure of the percentage of electromagnetic energy absorbed by the human body when it is exposed to the action of an electromagnetic field at radio frequency. The value 1.73 W / Kg refers to the amount of energy absorbed by the body of unit mass.
      Sincerely
      Staff Sicom

    • Good morning. I have a question. On the basis of the measurement of the criteria will be of the same smartphone, the corresponding value USA should not always be greater than EU?

      • Yup, typically it is so, However, the transmission bands are different in the two countries, so there may be unexpected results.
        Sincerely
        Sicom Testing

    • Dear Joseph,
      according to the European standard of the SAR value it is expressed as an average value of a corresponding cube 10 g of tissue. The cube (ideal) It is placed in the maximum exposure area. The SAR is expressed in watts of power per kilogram of tissue.
      According to the US standard value is expressed on a cube only 1 g of tissue. The thus measured value is greater than the European because the media is made on a volume that is a subset of the European and which contains the maximum peak exposure.
      good job
      Sicom Testing

  5. Good morning. The values ​​will be of the cellular usually refers to exposure of the head (ear) the person during the call. I do not find correspondence, in the tables that I find on the net, between these values ​​and those referring instead to exposure of the body. This last, on average, They are much higher than the first. How it is measured? Change something in the detection system? Thank you

    • The SAR measurement relative to the body is carried out on all sides of the product comparing it to a flat surface. The measurement of SAR relative to the head is carried out by combining the product to a head-shaped surface turning the speaker toward the ear.
      It is obtained a SAR measurement relative to the upper body to that of the head if the emission occurs mainly towards the back of the phone and if the antenna is placed so as not to approach the cheek during use close to the ear.
      Regards
      Sicom Testing

  6. In a typical double bed, I inadvertently left my Samsung Galaxy Note 4 access (even with the WiFi home to which your phone is connected) on my side (where I sleep) while my wife was resting in the afternoon, x a time of 3 / 4 hours.
    The distance between my sleeping wife and your smartphone resting on the bed was between 70 and 90 cm.
    (I was standing in another room, otherwise I would have immediately removed the phone, but I forgot to have it resting there and my wife saw him because randomly covered by the sheet).
    The question is: as they affect the SAR values ​​on the body at similar distances? And the WiFi to which the phone as it affects SAR value was attached?
    Thank you.

    • The SAR value decreases rapidly with increasing distance from the body. In just a few centimeters make a big difference. At distances She indicates exposure is negligible.

      Good day from Sicom Testing

      • Hi, I'm looking smartphone models taking into account low Sar. I do not know if priority is lower in relation to the head or to the body. So says the body we take advantage of the distance we, but if my use of the phone is as minority calls and auriculares..No I use is more convenient than the sar is low in the body especially?

        • Good morning Anna,
          generally low SAR values ​​are equivalent to greater safety. I carried out in the laboratory tests are performed on the devices operating at maximum power and the results are the maximum values ​​found in the worst case. In normal use of the device it is always advisable to resort to the use of hands-free headset, Therefore, it is appropriate to take into account a low SAR value for the body.
          Greetings from Sicom Testing

  7. Thank you for your previous answer. I have another question: SAR values ​​at the head I guess they relate to the use of the phone during a call. But I wonder if the SAR values ​​related to the body than the values ​​are always measured during a call (that, in reference to the body, would in my opinion not very significant) or during the normal activity of a cell connected to the internet (receive messages, whatsup, notifications, etc.). Thank you

    • The SAR is measured with the transmitter operating at maximum power and in all operating conditions. The indicated value is the greater between those measured. One proceeds in this way both in the case of the head of the body.
      In actual use the actual transmitted power depends on the distance from the base station, noise on the radio channel and the information content to be transferred. The data stream can also be variable in the case of voice call.
      There are also applications in which the device transmits information packets to a few days and there was the question whether it was appropriate to indicate the SAR of the worst operating condition even if in this case would have never been used.
      Both the European Commission that the American FCC concluded that it was still shown the SAR of the worst operating condition.
      Greetings from Sicom Testing

    • Good evening, I would have 3 Questions to Ask:
      1-I read that a terminal that uses more efficiently the radio module, while having a higher maximum SAR value, may produce less electromagnetic emissions compared to one that uses less efficiently. So if the SAR is not enough to assess the “safety”a smartphone, What else can you look?
      2-In addition, the American and European studies are done at the same distance from the source?
      3-When using the phone for longer messages or videos, it is better to just compare smartphones for SAR body or the head (since there will always be a low head equals a lower body SAR)?
      Thank you

      • Good morning Elisa,

        1 – The safety of a smartphone is guaranteed by the fact that it is within the preset limits of SAR. A product that exceeds these limits should not be placed on the market. A product that is within the limits can be placed on the market and is considered safe. The attempt to make further distinctions or classifications takes us on a pretty treacherous terrain.
        2 – The American and European studies are done at the same distance. However, there are technical differences in testing that lead to results not identical in the two cases.
        3 – the SAR “head” It represents situations in which the smartphone is used against the ear. the SAR “body” It represents cases in which the smartphone is used in contact with the body or hand.

        A good day to Sicom Testing

  8. Good evening, I would like to ask for information about the SAR value of a smartphone with a known US only SAR Level

    Head: 0.28 W / kg
    Body: 0.76 W / kg
    Simultaneous Transmission: 0.92 W / kg
    Hotspot SAR: 0.70 W / kg

    Is there a way to calculate or understand what the EU values ​​in SAR?

    • Good morning,
      there is no way to derive the values ​​of European SAR those USA, We must effetuare the measurement by applying the method prescribed by the European standard.
      Lacking the value of European SAR probably the product needs to be fully certified for the European market understand all aspects required for use of the spectrum, Electromagnetic compatibility and safety.
      Sincerely
      Sicom Testing

  9. Hello, I wondered if there existed a variation of the SAR / DAS on a mobile phone with Wi or enabled mobile data and without WIFI / mobile data ? And can there be a correlation between the capacity of the battery of a smartphone and SAR ?
    Thank you.
    cordially

    • The SAR measurement is used to verify that a product meets the health requirements for users. This is done taking into account all radio interfaces present.
      The exposure of each individual user is different and depends on many variables. First, the distance at which the product is used. Secondly they can perhaps affect the services that are activated, but only if the product is kept in contact or close to the body.
      Battery consumption is not suitable as the SAR indicator because it depends on many factors: a running application or the active GPS receiver may increase the consumption without that there are implications for exposure.
      However, even if we measure the consumption of only radio transmitter, this would not be significant to evaluate the SAR since the characteristics and the position of the antenna in the product affect significantly on the exposure value.

      Greetings from Sicom Testing

  10. Ciao, 1. What SAR indicators should I use when buying a phone (USA o UE) ??? 2. Because some phones have no sar values ​​in the technical specifications, but they only indicate that they are EU certified ??? 3. Because the same sar has different sar values ​​for US and EU measurements?

    • Good morning.
      1. The SAR limit for the United States is 1,6 W / kg referred to a mass of one gram of human tissue, while the one for Europe is from 2 W / kg referred to a mass of 10 g of human tissue. SAR measurements are done in two ways, head e body: head refers to when the product is used near the ear, body refers to all other cases where the product is used close to the body.
      2. When the equipment is within the European limit indicated above, the product is considered safe according to European regulations and can be placed on the European market.
      The SAR values ​​obtained in the various conditions of use are additional information.
      3. Because the value refers to different quantities of mass exposed, also in some cases there are small technical differences in the execution of the test.
      Greetings from Sicom Testing

  11. Good morning,
    1- with frequencies a 27,5 GHz del 5G , the carrier frequency of the electromagnetic fields of mobile phones will also vary ,to date, the exhibition e’ calculated between 100 kHz e 10 GHz ?
    Thank you

    • Good morning.
      Human exposure to electromagnetic fields from mobile phones is assessed through SAR measurements. In the case of portable devices operating in the frequency of 27,5 GHz, if at the time of the assessment, systems approved for the measurement of SAR at these frequencies will not be available on the market, the other measurement techniques available for human exposure will be used. The limits for human exposure of the population have long been defined also for those frequencies, both for the general public and for workers.
      Greetings from Sicom Testing

  12. Ciao, I have several questions,
    -I bought a Samsung phone with 1.6 of Sar in Body with European Union measures It has some negative effects?
    -The envelope can deduce and create more waves?
    -In airplane mode the Sar is reduced to 0?
    -SAR tests are at maximum power? Bluetooth, call, mobile data etc.?

    • Good morning,
      – the European maximum limit of the SAR value is 2 W/Kg, so the value 1.6 is within limits;
      – the envelope generally has no effect on the creation of electromagnetic waves;
      – Airplane mode does not guarantee disabling all wireless functions. However, the electrosmog produced by the mobile phone, tablet or other instruments in this operating regime is very small and the consequent exposure to electromagnetic waves is to be considered negligible;
      – in the laboratory, SAR tests are performed on devices operating at maximum power.
      Greetings from Sicom Testing

  13. Good morning.
    Sorry for the question, I didn't really understand the difference between the European and the American measurement.
    For example my phone has much lower values ​​with the American measurement but with the European one very high values.
    As a result, I actually wonder why and if it actually could cause problems since it has such high values ​​in Europe ?
    Thank you

    • Good morning,
      there are various technical details for which the European SAR measurement is different from the American one.
      If the product has values ​​within the limits set, it can be considered safe.
      Greetings from Sicom Testing

  14. good morning.
    Respect (or failure to comply) by an electronic device the expected SAR limits have an impact on the CE certification of the product itself?
    Thanks for the reply

    • Good morning,
      certainly the product that exceeds the expected SAR limits cannot be placed on the market.
      Greetings from Sicom Testing

    • Good morning,
      the area of ​​the body that is affected by the electromagnetic fields produced by consumer equipment is typically quite concentrated. The measurements are made on a rather large area, for example the whole head or a large area of ​​the body such as the torso, but of all the measures that are taken one goes to look for the part that receives the most power.

      For technical reasons the resolution of this evaluation is not referred to a point but to a small volume. This volume in European standards was set in 10 g of tissue, while in US standards (developed later) was defined in 1 g of tissue.

      It's’ a bit’ like the resolution of a TV: in the US case it's a bit of a resolution’ highest, but this does not change the meaning of the image we are seeing, because in any case the measure is expressed in power / volume involved, it changes a bit’ the sharpness of the image.
      In all cases, the complete image concerns a larger part of the body.

      Greetings from Sicom Testing

  15. salve , I would like to know if the American limits are more’ restrictive ie’ safer than European ones . Yours sincerely

    • Good morning,
      there are some differences in the way of conducting the measurements that do not allow a precise direct comparison of the results.
      However, the US base limit is more restrictive than the European one, being of 1,6 W / kg vs. 2.0 W / kg.
      Greetings from Sicom Testing

    • Good morning,
      SAR tests can only be performed in specialized laboratories.
      The SAR value is reported in the product user manual.
      Greetings from Sicom Testing

  16. Ciao,
    Sono davvero confuso sulla scelta di uno smartphone con un basso SAR.
    SAR testa: 0,279 W / Kg
    SAR corpo: 1.525 W / Kg
    Questi valori sono alti o bassi?
    Un telefono con valore di SAR inferiore è più sicuro?
    Quale dovrebbe essere il SAR per la testa o il corpo inferiore?
    Grazie,
    Racheli

    • Good morning,
      to understand if the SAR value of a radio device is low enough, it is enough to remember that in Europe the permitted limit of the SAR value is 2 W / Kg su 10 grams of tissue, while in the United States and Canada the limit is 1,6 W / Kg misurati su 1 gram of tissue.
      A device with SAR value within these limits can be considered sufficiently safe.
      Greetings from Sicom Testing

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