More Information

The AM11 Acoustimeter is our most powerful radiofrequency (RF) / microwave detector. It measures both peak and average signals using a combination of LEDs and number readings on an bright text screen. The AM11 detects almost all modern wireless technology, including mobile phones, cordless phones, smart meters and Wifi. The instrument is suitable for those with severe electrosensitivity as it is sensitive down to 0.02 V/m. It also has an audio output that helps determine the source of the exposure.

The Acoustimeter will help you quickly understand your RF environment. It accurately measures all incoming radiation from 200 MHz to 8000 MHz (8 GHz), and was designed using many years of real life measurement experience.

The readings are shown on both an clear "OLED" text display and two sets of LED lights. The LEDs update rapidly, helping you to find hot-spots. The text display offers high accuracy with a lower update speed, giving you time to take note of the readings. You can easily determine what kind of device is causing your exposure using the internal speaker. Sound samples are available to help you identify what kind of signal your Acoustimeter is measuring. The sounds made by different devices change with time, so these are a rough guide only. If there are a number of sources of exposure, the sounds may mix and be harder to recognise.

If you can hear a very quiet "hissing" noise when no LEDs are lit, this is normal. This is from the internal workings of the Acoustimeter, and is therefore of no concern.

The Acoustimeter reads differently from some meters as:

1. It has a very fast response (up to over 8 GHz and reacts to very short pulses)
2. Peak readings are what they say – the highest sampled reading – and will react correctly to very short pulses that are regularly transmitted (such as from WiFi). The peak-hold reading on the OLED screen can be higher for some types of signal than the highest LED seen flashing as the Peak LED display does not show all the pulses in order to make it easier to see. The OLED peak-hold is the highest measured since "last cleared". It is cleared by switching the meter off and on again, or by pressing the "CLEAR (PEAK)" button
3. The Average reading is a true mathematical time-averaged rolling average of thousands of samples, updated 3 times each second. This gives the correct reading for DECT and WiFi and is much lower (DECT average power is about 0.01 of the DECT pulse power) than many other instruments which use the highest peak reading and then translate that into an equivalent average power. That is not correct as power is measured as total energy used/delivered per second and not the energy in a short pulse of say 10 milliseconds followed by a 990 ms gap. It is important that we understand this as most international standards are based on true average power (actually usually averaged over 6 minutes!).

N.B. The internal antenna is at the top rear of the case. Signals are best measured when the source is behind the instrument, but also quite good with the source to one or other side (particularly the left side away from the switches and volume control). It under-reads if the source is in front of the meter as the OLED display acts as an RF screen.

RF unit converter (signal strength and power flux density (PFD) for continuous (CW) signals)

Make sure you select the correct unit for power flux density before running the conversion:

Technical specifications

• Two line LCD displaying actual levels:
    » Peak exposure levels in V/m
    » Peak hold levels in V/m
    » Average exposure levels in µW/m²
• Two lines of LEDS displaying actual levels:
    » Peak exposure levels in V/m
    » Average exposure levels in µW/m²
• Measurement range: 200 - 8 000 MHz ±6 dB ±0.02 V/m
• Sensitivity (Peak Display): 0.02 V/m - 10.00 V/m
• Sensitivity (Average Display): 0.1 µW/m² - 250 000 µW/m²
• LEDs go from 0.02 V/m - 6.00 V/m (peak) and 1 µW/m² - 100 000 µW/m²
• Internal loudspeaker with volume control
• 3.5mm audio socket, which disables loudspeaker when in use
• Audio can be heard below 0.02 V/m
• Power source: 2x AA Alkaline or Rechargeable (1.2 - 1.5V)
• Power draw: 100-150 mA at 3 V
• Battery life: 20 hours
    » Typically 15 hours on two new 1500 mAhr AA alkaline cells and
    » Typically 25 hours on two charged 2700 mAhr NIMH rechargeable cells
• Size (mm): 190 x 102 x 33 (LxWxD)
• Weight: 280g, 330g with batteries

Documentation

Article - What's the difference between peak and average exposure?

Download Manual
Instrument updates from the manual
Improvements over the AM10

Example sound files

• Background Hiss (MP3, 79 KB)
• GSM Base Station (MP3, 45 KB)
• DECT (MP3, 111 KB)
• TETRA (MP3, 77 KB)
• 3G (MP3, 103 KB)
• WiFi (MP3, 104 KB)

Reviews

     

Left on Saturday, March 23, 2019

Very cool piece of kit - I use this to measure mobile/wireless radiation and the PF5 to measure electrical fields and magnetic fields. You learn a lot as you go along measuring different things. Can draw your attention to problems you otherwise wouldn't have noticed.

     

Left on Sunday, March 18, 2018

I am very impressed with the Acoustimeter.

It is very sensitive. With a little bit of time and ear training you can quickly tell what kind of source is emitting the electromagnetic waves. For example, on a mobile phone bluetooth has a different sound from WiFi...

I have tested it on cordless phones, microwave ovens, mobile phone towers, mobiles phones and various bluetooth devices, to name but a few.

The meter itself is quite pricey but it is one of a kind and I couldn't find anything like this anywhere else on the internet. My passion and interest in this area is what drove me to pay the large sum of money required to get my hands on one. It was posted to me via Royal Mail Special Delivery and came with a custom protective bag.

It was very interesting for me to know what I was being exposed to on a daily basis and the Acoustimeter really lets you "see" that.

     

Left on Tuesday, February 13, 2018

bONJOUR.
Je suis très satisfait de cet achat.
Son prix me faisait hésiter depuis longtemps, mais j'ai eu l'occasion d'utiliser un Acoustimeter prêté par une amie. C'est extraordinaire de pouvoir identifier par le son l'origine des émissions (WiFi, Buethooth, DECT, Téléphone Radars etc..)
Je ne peux que conseiller cet investissement.
De plus j'ai eu déjà l'occasion d'utiliser le service après vente d'EMFields pour un DEtekta qui était tombé en panne.
Tout s'est très bien passé et on m'a remboursé mes frais de port du retour.
Raymond TRICONE

     

Left on Saturday, March 25, 2017

Excellent product for sensitivity and and range of RF bands. It can also be used to find direction of RF field. It is bit pricey though for what is basically an Ariel, hence only 4 stars...

     

Left on Wednesday, September 14, 2016

Great product. Prompt delivery. Easy to use and very sensitive through a wide range of EMF. Well done.

     

Left on Wednesday, February 3, 2016

Rest assured that I have a very high opinion of the reliability and integrity of your products, the Acoustimeter's sensitivity to low fields, and today coincidentally a customer remarked on its ease of use.

A superb piece of equipment for the professional EMF investigator.

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Left on Wednesday, February 3, 2016

Thanks for this good information. Our group ADORES the Acoustimeter no matter what anyone says. It may not be a spectrum analyzer, but it tells us what we need to know and it duly impresses all who hear its messages.

We are your diehard fans till death (from Wi-Fi) do us part.

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Left on Wednesday, February 3, 2016

I most of the times use Acoustimeter at the beginning of a site survey, in exploratory mode, because I believe it is the most effective broadband meter device I own to get a first complete outline of existing RF signals, before attempting any narrowband analysis. I also found it to give consistent readings when compared to other measurement methods..

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Left on Wednesday, February 3, 2016

Thank you for your promptness and professionalism.
Stefan.

     

Left on Thursday, October 29, 2015

Excellent product, very accurate and easy to use, excellent service from EMFields Solutions, thank you, Sarah, thank you, EMFields Solutions!

     

Left on Monday, October 26, 2015

This device is a God send for me

     

Left on Wednesday, April 29, 2015

I am delighted with this meter. It is easy to use and the LED displays and the sound make it easy to identify most sources of microwave RF signals. Very helpful for me.
BS
Southampton


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Left on Wednesday, April 29, 2015

I bought an RF meter recently. It has been absolutely invaluable. I take it everywhere. I have discovered some amazing information. Like coastal paths near St. Agnes Head Cornwall, beautiful and wild but with radiation reading of greater than 6.0 V/m. Shops and high streets can be in the range 1.0 to 5.0 V/m. I wouldn't be without it now. I have mapped out very low emissions routes to walk in my neighbourhood.

PG (purchased Jan 2015)


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Left on Friday, January 2, 2015

Hi!
I'm very satisfied with your service, which was fast and well organized. I'm also satisfied with my Acoustimeter. Thank you!

Best wishes,
Robert H. Westerlund
(You can visit me on YouTube and/or my little homepage. :)

     

Left on Tuesday, September 30, 2014

Ottimo venditore, ottimo prodotto, affidabile, consigliato!