ACI Concrete Strength Testing Technician Practice Test

What aspect of the test machine must be verified before beginning the test?

1. That it has enough power

2. That it is clean

3. That it is calibrated

4. That the load indicator is zero

The correct answer is: That the load indicator is zero

Before beginning a concrete strength test, it is crucial to ensure that the load indicator on the test machine is at zero. This step is important because if the load indicator does not read zero before any load is applied, it can lead to inaccurate measurements of the applied load during the test. A non-zero reading may suggest that the machine is already under some load due to previous tests or mechanical issues, which can skew the results of the current test. By confirming that the load indicator is zero, you establish a reliable baseline for the test measurements, which is essential for the integrity of the testing process and the accuracy of the concrete strength results. While other aspects such as ensuring the machine is clean, calibrated, and has adequate power are also important for overall functionality and accuracy, the immediate verification of the load indicator being at zero is a critical step that directly impacts the test's validity.