DIY Ultra Sensitive EMF Detector © GPL3+
https://create.arduino.cc/projecthub/mircemk/diy-ultra-sensitive-emf-detector-4be895

A simple to build, but very sensitive electromagnetic field detector.

This is a simple device capable of detecting very weak electromagnetic fields. The relative field intensity is displayed on the LCD display and at the same time are given a buzzer sound signalization and LED light signalization. In this case the sensor is a plain copper wire, with a 1.5mm diameter, but you can use any piece of wire or metal tile. Sensitivity can be adjusted via code, and also by changing the value of the resistor connected between A0 and grounding

the circuit is very simple and consists of Arduino Nano microcontroller and several external components.

Extech model 480836 handheld meter at $279 to characterize the accuracy. We’ll be comparing it to two other ETS-Lindgren (calibrated) meters.

The Extech 480836 E-field meter is a hand held unit that covers a claimed 50 to 3500 MHz at up to 108 V/m. The 9.3 x 2.4 x 2.4-inch unit comes with a padded box and 9V battery and fits easily into the hand. The E-field antenna is a three-axis design for omni-directional (isotropic) reception, but can read out each axis (or the combination) individually. The manufacturer claims a frequency range of 50 to 3500 MHz, but admits measurements are “optimized” for 900, 1800 and 2700 MHz – basically, the mobile phone bands and Wi-Fi.

I was a bit disappointed to learn the unit was only guaranteed accurate in certain frequency bands. However, the unit does come with a universal (not specific) calibration factor chart.

we set up a 1m measurement range on top of my ping pong table. We borrowed a couple of calibrated E-field meters and proceeded to compare all three against a standardized source.

The results were better that I thought in the frequencies above 600 MHz and all three meters compared to within 1 V/m across those frequencies. The Extech, however, had some major departures from the others in the bands 50 to 150 and 400 to 600 MHz.

The units of measurement (V/,m, A/m, uW/cm2, and mW/m) are controlled by one button.

Extech makes a higher-end model 480846, that measures from 50 to 8000 MHz.

Repeated experiment failures have led to a most unexpected discovery about how songbird orientation may rely on the quantum phenomenon of electron spins. Researchers found out that very weak electromagnetic fields disrupt the magnetic compass used by European robins and other songbirds to navigate using the Earth’s magnetic field.

Neither power lines nor cellphone signals are to blame for the electromagnetic field effect on the birds, according to the new study published in the 8 May 2014 edition of the journal Nature. Instead, the culprits consist of frequencies between 2 kHz and 5 MHz, such as AM radio signals and ordinary electronic equipment that might be found in businesses or private homes.

the team came up with the idea of putting a Faraday cage around the birds’ windowless huts to block the effects of nearby electromagnetic fields. Suddenly, the birds could navigate using their magnetic compass once more.

That allowed them to narrow down the troublemaking frequencies to the 2 kHz – 5 MHz range,

The surprise findings have left several mysteries for researchers. Such electromagnetic fields are much weaker than the lowest exposure limits recommended for humans by the International Commission on Non-Ionizing Radiation Protection (ICNIRP), and are also weaker than the minimum levels at which researchers expected any biophysical effects.

Electrical devices may disrupt the migration of some birds, a study suggests.

A German team has found that weak electromagnetic fields produced by equipment plugged into mains electricity and AM radio signals interfere with the animals’ “internal compass”.

They believe the effect is greatest when birds fly over urban areas.

The study is published in the journal Nature.

Prof Henrik Mouritsen, from the University of Oldenburg in Germany, who carried out the research, said: “At first, I was highly sceptical that this could be the explanation.

“But if you have seemingly unlikely effects then the proof needs to be much stronger – and that is why we have done so many experiments over seven years and it has taken a long time before we were confident to come out with this to the public.”

Over the course of the next seven years, he and his team carried out numerous experiments to look at how the weak electromagnetic field affected the behaviour of the robins.

In essence, he found that birds exposed to electromagnetic “noise” between 50 kHz and 5 MHz lost all sense of direction. But when the field was blocked out, they found their bearings again.

Prof Mouritsen said that migratory birds flying over towns and cities, where there are more homes and businesses that use electrical devices, would be most effected – and they would probably resort to back- up navigational systems.

“The birds wouldn’t be completely lost because they have three different compasses: a star compass, a sun compass and a magnetic compass, and they work independently of each other. As long as it is clear they should be fine with their sunset compass or star compass.”