- #1

- 9

- 0

Could you help me with the homework, please...

For the conventional resistance measurement used four electrodes: two current (A, B) into the country "deserts" and the current I between two measuring (M, N) is then measured voltage AU, resistivity, which is the goal of our measurement is determined according to Ohm's law; in its formula is needed to add a so-called. arrangements constant k, which depends on the distance of the individual electrodes. The calculated value is then referred to as "apparent resistivity" ρz, because it describes the whole "block" hemisphere, where penetrated current:

ρz = k * AU / I

Depth of this measurement is approximately 1/3 of the distance between the electrodes A and B. How far AB hypothetically you chose if you think that the resistance measurements would allow to determine the presence of a ditch.