ACI Concrete Field Testing Technician - Grade I Practice Exam

What is the correct action if the air content reading exceeds 9%?

1. Add more air to the meter

2. Measure the density of the concrete

3. Add calibrated cups of water to bring the liquid level within range

4. Stop the test immediately

The correct answer is: Add calibrated cups of water to bring the liquid level within range

When the air content reading exceeds 9%, the appropriate action is to add calibrated cups of water to bring the liquid level within the specified range. This step is crucial because the air meter needs to be accurate and functional to provide reliable readings. Overfilling the liquid level can result in erroneous air content measurements, so adjusting the water level ensures the accuracy of the test. In practical situations, maintaining proper liquid levels is key to achieving a valid test outcome. Accurate water levels help in creating the necessary conditions for the air meter to work properly, allowing for precise measurement of air entrained in fresh concrete. It's important to understand the implications of the other options. Adding more air to the meter would complicate the reading further rather than resolving the issue. Measuring the density of the concrete does not directly address the air content reading itself, as density is a different parameter. Stopping the test immediately could hinder the workflow unless there are safety concerns or significant errors in testing that warrant such a decision. Adjusting the liquid level is a critical step in ensuring that the test can proceed effectively and yield accurate results.