ACI Certification Practice Exam

What is the maximum time allowed between obtaining the first and final portions of a composite sample?

1. 5 minutes

2. 10 minutes

3. 15 minutes

4. 20 minutes

The correct answer is: 15 minutes

The maximum time allowed between obtaining the first and final portions of a composite sample is 15 minutes. This standard ensures that the sample remains representative of the material being analyzed, as factors such as evaporation, settling, and contamination could alter the characteristics of the sample over time. By adhering to this time limit, it minimizes the potential for changes that could affect the accuracy of the results, thereby maintaining the integrity of the sampling process. The specified duration reflects the balance between practical sampling procedures and the necessity of obtaining accurate and reliable results in quality control and testing environments. Maintaining this timeframe is crucial for compliance with industry standards and regulations, ensuring that the sampling and subsequent testing reflect the actual conditions of the material being assessed.