surface resistance between 2 points

[rab]

Hi,

I have a discussion with a collegue. We have material with 1 M/square
surface resistance. What is the resistance between 2 points (diameter 1 mm
round) seperated by 20 mm. Is there a formula somewere or a place to look.

Thanks
Ronald

 

[Larry Brasfield]

Hi, Hi.

I have a discussion with a collegue. We have material with 1 M/square
surface resistance. What is the resistance between 2 points (diameter 1 mm
round) seperated by 20 mm. Is there a formula somewere or a place to look.

Look for the formula giving the capacitance
between adjacent round conductors. Except
for the constant term and the fact that one is
per unit length and the other not, the formula
will be the same. Just substitute conductivity
for permeability per unit length.

 

[Jamie]

Hi,

I have a discussion with a collegue. We have material with 1 M/square
surface resistance. What is the resistance between 2 points (diameter 1 mm
round) seperated by 20 mm. Is there a formula somewere or a place to look.

Thanks
Ronald

not sure on your question format "1 M/square" ?

1 meter per square? or 1 meg ohm per square?

and when you say round?, are we talking about a
round like in a doughnut? or a sphere ?

 

[John Larkin]

Hi,

I have a discussion with a collegue. We have material with 1 M/square
surface resistance. What is the resistance between 2 points (diameter 1 mm
round) seperated by 20 mm. Is there a formula somewere or a place to look.

Thanks
Ronald

There is an equation. Google "surface resistance two contacts" or
something similar.

(rho/dz)log(L/r)/pi or something.

John