Why Did Our Geophysical Group Use a L&N Bridge Instead of a Slide-Wire Bridge?

Click For Summary
SUMMARY

The geophysical group utilized a Leeds and Northrup (L&N) bridge instead of a slide-wire bridge for measuring soil resistance in Yuma, Arizona, due to three primary reasons: superior accuracy, portability, and resistance to temperature-induced discrepancies. The L&N bridge's design minimizes errors that can arise from thermal expansion or contraction of wires, which is critical in high-temperature environments. This choice reflects a professional preference for reliable and efficient measurement tools in geophysical research.

PREREQUISITES
  • Understanding of electrical resistance measurement techniques
  • Familiarity with Leeds and Northrup bridge technology
  • Knowledge of the impact of temperature on electrical components
  • Basic principles of geophysical surveying methods
NEXT STEPS
  • Research the operational principles of Leeds and Northrup bridges
  • Explore the effects of temperature on electrical resistance
  • Learn about geophysical surveying techniques for water detection
  • Investigate the advantages of portable measurement instruments in fieldwork
USEFUL FOR

Geophysicists, environmental scientists, and engineering students interested in soil resistance measurement and the selection of appropriate measurement tools for field research.

hamburgler
Messages
22
Reaction score
0
My teacher gave us this problem to work on:

Homework Statement


Some years ago I worked with a geophysical group that was looking for water in the Yuma Arizona area. Boy what it hot! Because of the high temperatures in the summer, water was badly needed in large amounts to irrigate crops. Our crew inserted probes in the soil over large areas so we could measure the resistance of the soil and hopefully find water. The instrument that we used in this research was a Leeds and Northrup unit just like the one you used in your experiment. We did not use a slide-wire bridge. Give three reasons why a professional crew like I have described used a L&N bridge rather than the slide-wire bridge.

2. The attempt at a solution

1. A L&D bridge is far more accurate than a slide-wire bridge is in this situation.
2. It is more portable.
3. The heat may cause the wire in the slide-wire bridge to shrink/expand and cause discrepancies in the data.


The last two are just shots in the dark because I can't think of anything else beyond accuracy.
 
Physics news on Phys.org
No one?
 
Please? lol
 
I think 1) is because of 3) which is the correct answer. I am not very sure what an L&D bridge is though. I assumed they consisted of the arrangement of resistor boxes usually seen in labs.
 

Similar threads

  • · Replies 10 ·
Replies
10
Views
5K
  • · Replies 46 ·
2
Replies
46
Views
8K
  • · Replies 1 ·
Replies
1
Views
2K
  • · Replies 14 ·
Replies
14
Views
7K
  • · Replies 1 ·
Replies
1
Views
10K
  • · Replies 10 ·
Replies
10
Views
10K
  • · Replies 4 ·
Replies
4
Views
9K
  • · Replies 8 ·
Replies
8
Views
5K