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Archaeology Resistivity Meter

kltm

Hi I'm looking for ideas on an update to a resistivity meter for archaeology. The only published designs for diy were in 2 magazines. One was published in 1997 and the other in 2003. I have copies of both articles available. The reason behind this is the current high cost of available equipment, usually well beyond the reach of most archaeological groups. I've attached a basic block diagram. In the first magazine article the meter is very basic. It relied on the operators to write down the reading given as the survey was taken. Given that a normal survey grid is 20m x 20m and 1 reading is taken on every sq mtr there would be 400 readings to write down and then input into a program used to interpret the results. The later article is really an update to the first where a PIC has been added to record the readings. This again is prone to error, because eadings are taken manually by pressing a button.

I'm sure given the advances in electronics there must be better ways. 

 

 

 

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  • in reply to kltm

    I posted about the batteries I bought from Amazon in post 190 of this thread and Shabaz posted about the holders he bought from Aliexpress in 196.

     

    Neither post (nor the Aliexpress web site) has dimensions.

     

    The battery design is a Sony thing, so far I have not found a drawing with detailed dimensions.

     

    The holder Shabaz found is this one:

     

    https://lilliputdirect.com/index.php?route=product/product&product_id=824

     

    Lots on Ebay, including chargers and dual socket things at pretty low prices.

     

    I searched for np f970 adapter

     

    If you don't bother with the official mounting but dropped it (the battery) into a suitably shaped hole with to prongs at the bottom you could have a lif with thumbscrews to seal it up and hold them in place.

     

    MK

  • in reply to kltm

    Hi Ken,

     

    It's a Sony design intended for cameras but many manufacturers produce it, so it is unlikely to go obsolete quickly. It is called Sony NP-F sized, there's a video about it here:

     

    But any 7.4V LiPo ought to be fine, i.e. it is a decision the constructor can make. Some may already have (say) Canon or Nikon batteries so may prefer to use that. But personally I like the Sony design, it has large circular contacts, which feels more reliable for projects with low-cost battery holders.

     

    Also, maybe a small piece of foam is needed? since there could be shock or vibration, and double-check the lock on the battery-holder is sufficient or not. I don't have a mechanical background so I don't know what other precautions to take, however it could also be worth mounting the battery holder on some shock-absorbing material too.