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Measure EMF/EMR (DIY)?

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The most simple way to measure Electromagnetic Radiation

The most simple way to measure the EMF/EMR radiation  is to measure it where people usually stay for long time like:

  • The sleeping bed
  • Working desk/station
  • sofas/couch
  • kid's playing room

How to? 

  1. Just hold the meter high (in 3 Axis meters that all you need to do, in a single axis meter measure in Y, X, and Z axis and right down the square rote of  Y2+X2+Z2)
  2. Don't move
  3. Read the measurement 
  4. When the reading gets steady, Write down the values in a table.  If the measurment keep changing white down the Max, Mix and the value that is displyed most of the time.
  5. Repeat this process several times a day until you understand the radiation patterns

Which level is safe?




 
Picture - measuring where people stay for long periods of time



Before We start let's review some basic but important stuff


Several ways to measure electromagnetic radiation

It is important to know the difference between the different types of Electromagnetic Radiation (EMF/EMR) measurements. Every type of measurement will have a different focus, different methods and in some cases you should use different meters. The right meter should be chosen according to its characteristics and not only according to the frequency that it can measure. 


Frequency

Electromagnetic radiation sources can be divided into 2 frequency types, low frequency (power line, power transformers) and high frequency (RF, DECT, Mobile phone, microwave). Some meters can measure both types, some can measure only one. 


Read more about Electromangtic Radiation (EMF/EMR) source by frequencies: http://www.norad4u.com/knowledge/emr-sources-by-frequency 

Read more about Electromagnetic Radiation (EMF/EMR) measurement: http://www.norad4u.com/monitor 

Read more about home use meters: http://www.norad4u.com/monitor/home-emr-meters 



Meters sampling rate 

When the radiation level is changing rapidly (like in some digital radiation sources like 3G and 2G mobile phones, WiFi routers and etc.) it is very important to use electromagnetic radiation meters with a high sampling rate. If the sampling rate is slow, for example once a second like in some simple meters, the measurement outcome of a WiFi router will be very low, when in reality it picks to high levels several times in a second. I usually use electromagnetic radiation meters with the highest possible sampling rate. 


Average measurements 

In some cases it is the custom to make an average out of the levels of radiation that were measured. It is recommended (but not a must) to make a note of the minimum and maximum values that were measured. When average outcomes are reported it will usually mean that the picture revealed by the report will be very partial and limited since the peaks and high values that happened in some of the time were averaged by low values that were measured most of the time. In most cases I don't average my measurements. I try to get a clear and full picture and try to understand what causes the high peak levels. 


Measuring over long periods of time 

When the Radiation levels are changing throughout the day there is a need to measure them during all the hours of the day, sometimes for several days. In most cases when this is the need you have to use electromagnetic radiation meters that has the option to monitor the radiation levels through the day and night, and to store all the results in an internal memory, which can later be reviewed, examined and processed . The most recommended meters for this operation are meters that can be connected to a PC for data acquisition, extraction, real-time and offline analysis and display of all the information gathered during the measurement. 


Multi frequency and multiple sources measurements

Please note that most of the High-frequency electromagnetic radiation meters that I encountered to date (both professional and simple) are not able to measure multiple frequencies and multiple radiation sources correctly (mobile, WIFI, cellular antennas, cordless phones, etc.). This limitation is due to the difficulty of measuring and summing up all the radiation levels in all the frequencies. Therefore the measurement of radiation sources that emit RF radiation in several frequencies (eg: WIFI, mobile phone antennas mailman third or cellular) or measuring several radiation sources at once may not be accurate and the results will generally be lower than the radiation levels in reality. It is still possible to use these meters to expose radiation sources and to understand how to shield and how to reduce your exposure from them. The only why to measure multi-frequency and mutli-sources environment is by using a vary fast spectrum analyzer.




Different Types of EMF/EMR measurements

If you want to do the most basic and easy measurement please read the "Measuring radiation levels in places you stay in" chapter in this page.


Official protocol of Electromagnetic Radiation testers in Israel 

The official measurement protocol was created by the Israeli ministry of environment protection and all radiation testers in Israel are obligated to follow it. The environmental protection ministry supervise environmental sources of radiation like mobile phone towers and therefore this protocol is meant to measure these kind of sources (that are located in the environment) even when the measurement is done inside the house. The environmental protection ministry will allow the tester to step outside the protocol, if the customer requests it, but the outcomes of these measurements can't be included in the official report but only as an appendix. 


Protocol's instructions

High – all measurements should be taken at the height of one meter above the floor, in case there is an under floor heating it is allowed to measure 20 cm above the floor. 

Location – the tester must measure in four corners of the room, one meter from the walls and also at one point in the middle of the room. The tester can also measure radiation levels in more locations in the room but he is not obligated to do so. If the room is too small for several measurements, the test should measure only in the middle of it. 

Don't measure next to windows or radiation sources. 

The outcomes that appear in the official report are sometimes average calculations of the measurements that were done in the field. I think that this method does not give the whole picture and can cause, in some cases, disinformation especially when the costumer wants to identify the radiation sources inside and outside the house and in case he wants to understand where, when and what where the highest levels. 


Room background test 

When you need to test the electromagnetic radiation background levels inside a room you better start with the official protocol above. You need to stay one meter from the walls windows doors and radiation sources inside the room. This kind of measurement can show you the background levels inside the room. It is recommended to use an advanced electromagnetic radiation meter that gives a numeric indication of the radiation in all three axis, with fast sampling rate and with a clear and detailed display. A simple electromagnetic radiation meter can give you only a raw estimation of the levels. It is recommended to repeat this measurement twice, once with the radiation sources (cordless phones, WIFI routers, a CRT TV and etc) inside the house turned on and the second time when they are turned off. Analysis of these measurement outcomes can show you what the background radiation levels in the room are, and how the radiation sources affect these levels. If you want to understand the effect a single source has on the background levels in the room you can also repeat the test when only this source is turned on. 



Searching for radiation sources in a room: 

All types of electromagnetic radiation meters, even the simplest ones, can be used for searching radiation sources in a room (the meter should be for the same type of electromagnetic radiation as the source emits, either high frequency-RF or low frequency). All you have to do is to scan the room step by step, meter by meter. Whenever the meter shows an increase in the radiation levels that means that you are getting close to a source. If the radiation levels are dropping you are getting away from the source. It is recommended to use a meter with voice indication that makes it easier to notice changes in the radiation levels without looking on the meter’s display. 


Scan key points: 

  1. Scan in the room 3 times, once on the floor, a second time at one meter high and then at the hight of a human being’s head. 
  2. The scan should include all the parts of the room. 
  3. Use a clear scanning pattern that was planned before the test started (from center to the walls, or from one side of the room to the other side. 



Searching for radiation source from other rooms 

When searching for radiation sources outside the room we should focus on the border areas of the room with other spaces of the house (other rooms and floors) and with the outside, like walls, windows, doors, rooftops and underground spaces. 

When there is a high level radiation source outside the room, the first sign for that will be medium to high radiation background levels inside the room itself. 



Examples: 

  • When there is a high current electric wire inside the wall, the low frequency that is created around the wire will penetrate the room. If you scan the wall, vertically and horizontally  with a Low frequency electromagnetic meter the meter will show high radiation levels near the wire, and will enable you to expose the wire as the radiation source. 
  • In case there is a DECT base station next to the wall in the next room, the first signs will be medium to high levels of high frequency radiation inside the room. When the right wall will be scanned the radiation levels will increase as the meter will be closer to the DECT phone location, until it will reach the maximum measurement. 
  • In some cases when there is a radiation source in the next floor or in the floor below, there will be high radiation levels next to the ceiling or floor. 
  • When there is a high frequency radiation source outside the house, for example a mobile phone mast, the meter will show high levels of high frequency electromagnetic radiation mostly next to the window, and in some cases even on the wall which are in the direction of the mobile phone mast. 
  • When there is a low frequency radiation source in the near vicinity of the house (like an external electric power converter or high voltage electric power wiring) you will be able to measure high levels of extreme low frequency electromagnetic radiation in parts of the rooms of the house which are close to it (low frequency electromagnetic radiation passes easily via walls). 
  • When there is a CRT TV on the other side of a wall you will be able to measure high levels of low frequency electromagnetic radiation in the room, the pick will be on the wall next to the location of the TV (on the other side). 
  • When there is an external radiation source outside the room that radiates in medium or low levels, for example a wifi router or a small power converter  it will be difficult to locate the source by doing measurements in the room next door. In order to do so you will need to use a very sensitive and accurate advanced electromagnetic meter with a detailed display. In this case it is recommend taking a look inside the rooms next door in order to get some clues for the radiation source that can influence the measurement. 
 Sleeping bed.  Low frequency radiation sources from the bed sides and from the next room are marked in red.
 Living room with an aquarium filter, a TV and some audio and video equipment.  LFE radiation sources are marked in red. The radiation emitted reaches the next room (see pictures above).
Kitchen  ELF source is marked in red.


Measuring radiation levels in places you stay in. 

One of the most important measurements to be done inside a house is to measure the electromagnetic radiation levels in all the places in which you might stay in for a long time (more than 5 minutes). Examples for such locations in the house can be found in the following list: 

  • Sleeping Bed 
  • Home office station 
  • Kids Gaming-playing room 
  • Desk 
  • Dining Table 
  • Pc station 
  • Sofas
  • Sitting arrangement, sofa 
  • Living room 

The technique is to measure on top and next to the place in which the human body will be, and to try and understand what will be the radiation level and for how long the body will be exposed to it. In addition you need to try and figure out which radiation sources influence the radiation levels at this point. 

In the past I came across people who told me that they found a radiation source on their home working station desk, but they didn't think that it was serious since they sit next to it only for a short time. When I asked them for "how short?", they replied that they use it for half an hour to one hour each day. I just want to make it clear; I think that every exposure to electromagnetic radiation is not good and should be minimized as much as possible, and if possible to reduce it down to zero. Half an hour a day is not a short time as much as exposure to radiation is concerned, it is a lot of time. Whenever there is a radiation exposure it is highly recommended to try to find the source and turn it off so there will be no radiation emission (no radiation for you :-)  ) . 


bed room

Sofas

Home office room

Identify radiation sources outside the house. 

In order to identify high frequency radiation sources outside the house you need to use a directional radiation meter (the meter should have a directional antenna). The trick is to hold the meter in front of you and to scan the 360 degrees around. When the meter will be directing to, or will be closer to a radiation source, the radiation levels will usually be higher than when the source is not in front of the meter or far away from it. 

If you are using a 3 axis meter it is best to configure the meter to measure only in the axis which is parallel to the axis of the radiation source (for example axis Y for mobile phone masts). 



Identifying low frequency radiation sources outside the house is trickier since low frequency electromagnetic radiation is less directional than the high frequency. The search for the source should be based on getting closer or going away from the radiation source while trying to look and guess where the low frequency radiation sources are located in the near vicinity.



More about EMF/EMR Monitoring/Measuring on this site:

EMF/EMR measurement main page


How to measure EMF/EMR (DYI)

home use EMR meters

Home use EMF/EMR meters

professional EMR tester

Professional EMF/EMR testers



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