EPE resistivity meter

[rezamery]

Could you please introduce me a company or a dealer which sells EPE resistivity meter?
Thank you.

Regards,
Reza

[Unregistered]

You must buy the magazine (back issue on CD-ROM) from EPE and build the meter yourself. Support the mag...they publish good stuff. It was published in two parts: May and April 2003. Here is the link:
http://www.epemag.wimborne.co.uk/projects2003.html

[golden_greek]

EARTH RESISTIVITY LOGGER PROBES

for earth resistivity can i use bronze rods or must be is from copper or other metal?
THANKS

[Carl-NC]

Bronze should work fine, or most any metal.

[golden_greek]

Hi Carl
i have make EPE EARTH RESISTIVITY METER and EPE MAGNETOMETER
to magnetometer i can download to pc but from earth meter i cant.
have u any idea?
THANKS

[golden_greek]

i have another one question about earth resistivity
when i connect a herz meter to probe must show anything or not?
THANKS AGAIN

[Carl-NC]

Don't know why you can't download data... I've built both of these boards but have never finished and tested them, so I can't help much.

Yes, I believe the ERM uses an AC signal, so you should be able to get a reading on a frequency meter. However, it's a pretty low freq, and some meters have trouble with low ranges.

- Carl

[Unregistered]

The EPE ERM uses 137 Hz which is a pretty common frequency for ERMs as it is not a harmonic of 50 or 60 Hz. For the probes you can use 12 inch bolts and get a metal work shop to cut off the heads and grind the ends to point, you can then bolt them onto a frame.

Nick

[golden_greek]

i found the problem with connect to pc
just read this
Earth Resistivity OCX Notes 08OCT03
If this text is not wrapped, click on EDIT (above) and select WORD WRAP

Since I finalised the Earth Resistivity Logger for publication, reader Joe Farr provided EPE with a specially written program that allows legal access to Visual Basic's own serial control I/O facilities. This option has previously only been available to readers who have a registered version of MSCOMM (as Robert Penfold has discussed many times through his Interface series). Joe's serial OCX facility was published in full in the Sept '03 EPE issue.
A section of Joe's OCX program has been built into this Earth Resistivity and Magnetometer program and replaces the DLL-based download software described in the EPE Earth Resistivity articles. Joe's OCX provides a far more reliable download option than the original DLL option offered.
A further advantage of Joe's OCX program is that it allows a bargraph to display the progress of the data input procedure. It is also likely to be better at detecting input data problems as it uses a handshake procedure to communicate with the PIC, inputting the data in blocks of 256 bytes.
The Magnetometer hardware has been designed to only use Joe's OCX interface and does not need any changes to be made to hardware or software.
However, to use Joe's option with the Earth Resistivity hardware, several changes need to be made to its PCB, without which the facility cannot function and the ER data cannot been downloaded.
MODIFYING EARTH RESISTIVITY
The following changes are required to the Earth Resistivity PCB to suit the use of Joe's OCX:
1. Cut the track (0V) connecting to IC7 (MAX232) pin 13.
2. Connect IC7 (MAX232) pin 13 to 9-pin serial socket SK3 pin 3.
3. Connect IC7 (MAX232) pin 12 to IC5 (PIC) pin 18 (RC7).
This action allows the PIC to receive handshake data from the PC.
To set the PIC program to respond to the correct serial data transmission routine, initiate the following procedure:
1. Before switching on power, press and hold down the Mode switch, S6.
2. The screen will go into serial path change mode, alternating at about one-second intervals between a display saying "SERIAL PORT NORM" and "SERIAL PORT OCX ".
3. Release switch S6 when the OCX mode is shown. This mode becomes the active path mode and is also stored into the PIC's data EEPROM, to be recalled next time the program is run.
4. On release of switch S6, normal running of the PIC program resumes.
It should be noted that readers who wish to make their own changes to the ER and Magnetometer Visual Basic source code cannot make use of Joe's OCX input option unless they have installated of Joe's full OCX facility according to the details given in EPE Sept '03. Attempting to examine the ER/Mag source code without Joe's OCX fully installed will generate an error condition because of the presence of Joe's sub-program I use.
To repeat - you do not need to make any hardware changes if you are using the Magnetometer.
John Becker 08OCT03

[nelson]

Earth resistivity meter and logger

Hi, im almost finishing the earth reistivity meter and logger published by Everyday Practical Electronics, year 2003, issues april and may.
So, now i need a guide to understand how this divice works. I only know, that it can detect deferences on ground resistivity, but don´t know how to set up the instrument. How i can read the information that the logger pass to my PC?
I heard that some of this circuits can work with two or more probes, but i have no idea how to place them.
Has you can see i have almost no idea on how to operate this system
So please any manual or help will be appreciated.
Regards
Nelson

i found the problem with connect to pc
just read this
Earth Resistivity OCX Notes 08OCT03
If this text is not wrapped, click on EDIT (above) and select WORD WRAP

Since I finalised the Earth Resistivity Logger for publication, reader Joe Farr provided EPE with a specially written program that allows legal access to Visual Basic's own serial control I/O facilities. This option has previously only been available to readers who have a registered version of MSCOMM (as Robert Penfold has discussed many times through his Interface series). Joe's serial OCX facility was published in full in the Sept '03 EPE issue.
A section of Joe's OCX program has been built into this Earth Resistivity and Magnetometer program and replaces the DLL-based download software described in the EPE Earth Resistivity articles. Joe's OCX provides a far more reliable download option than the original DLL option offered.
A further advantage of Joe's OCX program is that it allows a bargraph to display the progress of the data input procedure. It is also likely to be better at detecting input data problems as it uses a handshake procedure to communicate with the PIC, inputting the data in blocks of 256 bytes.
The Magnetometer hardware has been designed to only use Joe's OCX interface and does not need any changes to be made to hardware or software.
However, to use Joe's option with the Earth Resistivity hardware, several changes need to be made to its PCB, without which the facility cannot function and the ER data cannot been downloaded.
MODIFYING EARTH RESISTIVITY
The following changes are required to the Earth Resistivity PCB to suit the use of Joe's OCX:
1. Cut the track (0V) connecting to IC7 (MAX232) pin 13.
2. Connect IC7 (MAX232) pin 13 to 9-pin serial socket SK3 pin 3.
3. Connect IC7 (MAX232) pin 12 to IC5 (PIC) pin 18 (RC7).
This action allows the PIC to receive handshake data from the PC.
To set the PIC program to respond to the correct serial data transmission routine, initiate the following procedure:
1. Before switching on power, press and hold down the Mode switch, S6.
2. The screen will go into serial path change mode, alternating at about one-second intervals between a display saying "SERIAL PORT NORM" and "SERIAL PORT OCX ".
3. Release switch S6 when the OCX mode is shown. This mode becomes the active path mode and is also stored into the PIC's data EEPROM, to be recalled next time the program is run.
4. On release of switch S6, normal running of the PIC program resumes.
It should be noted that readers who wish to make their own changes to the ER and Magnetometer Visual Basic source code cannot make use of Joe's OCX input option unless they have installated of Joe's full OCX facility according to the details given in EPE Sept '03. Attempting to examine the ER/Mag source code without Joe's OCX fully installed will generate an error condition because of the presence of Joe's sub-program I use.
To repeat - you do not need to make any hardware changes if you are using the Magnetometer.
John Becker 08OCT03

[Unregistered]

How deep???

Hello,
in which depth can somebody detect an metalic object30x30x40cm with
earth restitivity meter???
Can somebody show me a picture of detection result?
Thank's Chris!!!

[Leto]

ERM

Hello,
in which depth can somebody detect an metalic object30x30x40cm with
earth restitivity meter???

For such a big object I suggest u use some Pulse Induction type metal detector with big (40cm to 1m) coil.
As for earth resistivity; you will not detect much of the metal (except if it is buryied very shallow) but the earth-fill of the hole whitch is usually more damp and so offers less current resistance. So what you'll see on earth resistance plot is area with low resistance.

[auric]

epe earth resistivity

hi
in the process of building the meter,
has anyone done any testing of the meter
can you increase the power ?
hope to use it to detect old river channels in sandstone country also any old workings underground; i hope down to 60 feet ;

cheers