×
INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!
  • Students Click Here

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

Jobs

Grounding grid resistance measurements in concrete

Grounding grid resistance measurements in concrete

Grounding grid resistance measurements in concrete

(OP)
Hello,

I would like to receive some feedback from your experiences to perform grounding grid measurements in a existing one and you need to determine the value of the resistance, there is a layer of concrete.
How do you determine the resistance value?

I mean, do you "make some holes" to bury the electrodes?
Is this the only method to obtain correct values?

Any suggestions will be welcome.

RE: Grounding grid resistance measurements in concrete

Measurements can be made with a layer of concrete on the surface.  Concrete is a porous material, thus with the aid of water the resistivity will not be high.  

Use a wire mesh to make contact with the ground when conducting measurements.  Pack some moist dirt over the wire mesh, this will ensure good contact with the surface beneath to conduct measurements.  

The idea is to have good contact with the earth for any type of tests regardless of surface.  With higher resistivity materials you will require better equipment with higher output voltage to drive current.  

Determine the resistance value by inspection of a fall of potential plot.   

RE: Grounding grid resistance measurements in concrete

(OP)
Hello,

Is there any other method to determine ground resistance?

Because, according to ths standards the only "recognize" method is the "62%" but, we arenot certain if there are some alternatives to simplified this.

I thank you in advance

RE: Grounding grid resistance measurements in concrete

The 62% method is only applicable for sites that have homogenous soil structure.  99% of sites do not have homogenous soil structure, thus the requirement to plot measurements and by inspection of the graph determine ground impedance of the ground grid under test.  

I recommend hiring a qualified testing agency to perform the testing.  There are many pittfalls that can be encountered.   

 

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources