make EPE earth logger more stable

[Mohammed]

hi every one ..

I have made earth logger for becker it is good but have some major problems ..

I have made 2 complete devices and every thing works just fine except one thing ... the stability ..

one of my two devices goes up and down in reading in 5 ohms variation ...

for example if test field resistivity is 150 ohms it gives you simultaneously 148 , 149 , 150 , 151 , 152 and go up and down through these values

and the second device goes up and down through 10 ohms variation ...

and this is too much variation in small resistivity soils ... for example if soil res. value is 50 it gives you values from 45 to 55 and this is 20% error range and this is a disaster if you making survey for a site that had a small variation in its soil ...

that is mean you can't catch a small variation in soil ...

is this problem from me or from the circuit it self ...

I have tested this device with usb to rs232 converter and works just fine in transferring reading to pc ...

I have used commercial resistivity tester that never change it is res. reading value not even 1 ohm variation ..

so it so bad experience to me with this device if it still have this bad resolution values ..



need your help carl please ...

thanks and regards..

[ishtar hunter]

Hi mohammed
I am bahram .
I have built earth resistivity for becker and i have a problem with this device . I sent to you a private Message.please read