ACI Concrete Field Testing Technician - Grade I Practice Exam

How long should the air meter be inverted and agitated for effective operation?

1. No more than three seconds

2. No more than five seconds, must be repeated for a minimum of 45 seconds

3. No more than 60 seconds continuously

4. It should not be inverted

The correct answer is: No more than five seconds, must be repeated for a minimum of 45 seconds

For effective operation of the air meter, it is essential to invert and agitate it for a specific duration to ensure accurate air content measurements in concrete. The correct procedure involves inverting the air meter and agitating it for no more than five seconds, and this process should be repeated for a minimum total of 45 seconds. This duration is crucial because sufficient agitation is necessary to dislodge any entrapped air bubbles in the concrete sample, allowing for a more accurate reading of the air content. When the air meter is agitated correctly, it ensures that the sample is thoroughly mixed, which enhances the reliability of the test results. The emphasis on repeating the agitation for at least 45 seconds underscores the importance of consistency and thoroughness in the testing process, which are key factors in obtaining dependable data. Understanding this procedure helps you ensure proper calibration of the air meter, leading to reliable assessments of concrete's air content, which is critical for evaluating its durability and overall quality.