Modifying an EMF Meter for Data Logging

Discussion in 'The Projects Forum' started by brettjb, Jul 25, 2010.

  1. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    Hello everyone,

    I am hoping that someone can point me in the right direction. I really know very little to nothing about electronics, so please bear with me should I use any incorrect terminology. I will do my best to describe my goals in the hope that someone can point me along!

    Introduction
    Being a paranormal investigator (the serious type, not the thrill-seeking), I seek to obtain data which can be documented and used comparatively against other data. As an example, IF there was a drop in temperature at the same time as there was an increase in EMF, I would want to show this on paper (here-say is not good enough). ;)

    Software
    Shortly I will be having software built for inputing data for comparative analysis (as I mentioned above). I will use data-logging tools to capture information such as temperature over a time period. This data will be imported and then shown graphically. I wish to include various types of data such as temperature, and EMF.​

    The Problem
    There are many EMF meters available, but few have data logging capabilities. They also get rather expensive rather quickly.

    There are good reliable EMF meters that display the result on a screen, but have no data logging capability nor a voltage output port to log information.

    My reasoning is that as the data is being sent to an LCD screen, there should be an easy way in which this data could also be routed to a data logging device. ​

    Could anyone please make any suggestions as to possible ways of achieving this outcome?

    I want to record EMF readings, at a rate of approximately 1 reading every half a second (for any duration set). The goal is to record this as a CSV file which can then be imported into my software.

    I will not be doing this myself, but am hoping to have directions in which I can contract a local electronics crowd to undertake the changes. I am hoping to find a cost-effective solution as I will need to be doing this for numerous devices. My goal now is to find a way to do this, so that I may direct someone to undertake the work.

    Thank you for taking the time to read this.

    Regards,
    Brett
     
  2. tom66

    Senior Member

    May 9, 2009
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    You will find it difficult to interface with an LCD display due to the complex signals being sent. The logging part will be easy; the decoding part will be hard. Usually, a square wave signal is sent to each element on the display, and there are several 'back planes' which are grounded individually. By doing this fast enough, you get a display. So you can use say 50 connections instead of 180. But you will need to figure out how the product is doing this and I don't think the manufacturer would give this info away for free.
     
  3. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    Thanks Tom66.

    Is this something I could take to an electronics place and have them make the alterations in some other way? For example, could it have a voltage output and use a voltage data logger, then do the calibration in the software?

    Perhaps there is a different way this could be done?

    Thanks again.
     
  4. tom66

    Senior Member

    May 9, 2009
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    The question is, what is the "EMF" sensor? Does it have a voltage output or is it just some kind of digital circuit? If it's a voltage sensor, you can go cheap and get a datalogging multimeter for about US$100. This would give you a list of voltages, you could use a spreadsheet to translate it into whatever numbers you want.
     
  5. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    Thanks for that. I'll have to chase that up. If it is not a voltage sensor, is there a different approach that I could take?
     
  6. tom66

    Senior Member

    May 9, 2009
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    You could also get a logic analyser if it's a digital sensor. But again, these are professional pieces of equipment (they're also pretty pricey!), and it takes a lot of skill to use one, let alone decode a never before seen protocol. Show us a picture of how the sensor connects to the main board and I'll throw in a few more educated guesses.

    What does the EMF sensor do anyway? Pick up electromagnetic interference? Well you can build one for really cheap. Just get an old AM radio and tune it to an empty place on the dial. Attach a tape recorder and ... bingo, you have an electromagnetic interference detect-o-meter. Try it out... bring it close to your computer and you will hear loud buzzing. It can also pick up cell phone interference. I'm not sure about the paranormal, call me a skeptic; I also wouldn't know what to look for.
     
  7. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    "An EMF meter (or EMF detector) is a scientific instrument for measuring electromagnetic fields (abbreviated as EMF). Most meters measure the electromagnetic radiation flux density (DC fields) or the change in an electromagnetic field over time (AC fields), essentially the same as a radio antenna, but with quite different detection characteristics."

    - http://en.wikipedia.org/wiki/EMF_meter

    I'm a skeptic too, but I do find it interesting. Supposedly when a paranormal event occurs, there are fluctuations in the electromagnetic field. Whilst I have experienced using meters and seeing these fluctuations when in areas with NO source to have caused them, I still require more data. Supposedly there are temperature changes at the same time. I would like to be monitoring these and graph them together (and other things) to see what could be found.

    Personally, even IF there is something recorded in this manner, I don't think anything is the traditional 'ghost' that most think of. I'll consider it strange, and documentation of the strange occurrence would be great, but it will not prove ghosts or an afterlife is real at all. Just proves that there are strange environmental events occurring... :)

    Thanks again. Am considering trying to find a 2nd hand Fourier MultiLogPRO. It will allow capture of multiple events simultaneously, and avoid the need for messing around.

    Thanks Tom.
     
  8. tom66

    Senior Member

    May 9, 2009
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    Have you tried the AM radio trick? I use it just to check if older devices have life in them. If the tone is random and sporadic, they are running. But often when the lock up, the tone is continuous, like they are stuck or broken. (This applies mostly to old phones and computers... doesn't really work with modern stuff.)
     
  9. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    I've never tried it, or actually heard of it previously actually. Though I am growing an interest in these things as a result of my activities. Without having a great deal of to devote to learning, I guess that I am cautious about the time needed to become proficient. I will have to give that a go!
     
  10. beenthere

    Retired Moderator

    Apr 20, 2004
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    Last edited: Jul 27, 2010
  11. brettjb

    Thread Starter New Member

    Jul 25, 2010
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    Thanks BeenThere. I'll check out those links!

    It seems the simplest solution for me would be in finding some 2nd hand Fourier MultiLogPro units with magnetic field, temperature and voltage sensors.
     
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