Typically, when performing a close interval potential survey, pipe-to-soil potential readings are taken:
a. No more than 30 feet from the test station
b. Every 2.5 to 5 feet along the pipeline's length
c. On only 1% of the pipeline's entire length
d. Every 100 feet along the pipeline's length
Answer (1)
The problem asks about the typical spacing of pipe-to-soil potential readings during a close interval potential survey.
'Close interval' suggests frequent readings.
Option b (Every 2.5 to 5 feet) represents the closest interval.
Therefore, the correct answer is b.
Explanation
Analyzing the Options We need to determine the typical spacing of pipe-to-soil potential readings during a close interval potential survey. The term 'close interval' suggests frequent readings. Let's analyze the given options:
Option a: No more than 30 feet from the test station - This refers to the distance from a test station, not the spacing between readings along the pipeline. Option b: Every 2.5 to 5 feet along the pipeline's length - This suggests very frequent readings, fitting the 'close interval' concept. Option c: On only 1% of the pipeline's entire length - This implies sparse readings, not a close interval. Option d: Every 100 feet along the pipeline's length - This is a relatively large interval, not a close interval.
Determining the Correct Answer Based on the analysis, option b, 'Every 2.5 to 5 feet along the pipeline's length', represents the closest interval and aligns with the definition of a close interval potential survey.
Final Answer Therefore, the correct answer is b.
Examples
Close interval potential surveys are used to assess the effectiveness of cathodic protection systems on pipelines. For example, if a pipeline company wants to ensure their corrosion prevention measures are working correctly, they would conduct a close interval survey to identify any areas where the protection is insufficient. By taking frequent readings (every 2.5 to 5 feet), they can create a detailed map of the pipeline's potential and address any issues promptly, preventing costly leaks and environmental damage. This proactive approach helps maintain the integrity of the pipeline and ensures safe operation.
