Basic Wastewater Operator Practice Exam

What type of equipment should be calibrated daily at the treatment plants?

1. Portable DO probe/meter

2. AMP meter

3. Rain gauge

4. Staff gauge

The correct answer is: Portable DO probe/meter

The portable dissolved oxygen (DO) probe/meter should be calibrated daily at treatment plants because accurate measurement of dissolved oxygen levels is crucial for monitoring and controlling biological processes in wastewater treatment. These processes, such as aeration, rely on specific oxygen levels to maintain optimal conditions for aerobic microorganisms that break down organic matter. Calibration ensures that the measurements obtained from the DO meter are precise and reliable, which is necessary for effective process control. If the probe is not properly calibrated, it could lead to misinterpretation of the DO levels, potentially adversely affecting the treatment efficiency and compliance with discharge permits. Other types of equipment listed are not typically subject to daily calibration. While an AMP meter, rain gauge, and staff gauge may be important for specific monitoring tasks, they do not require the same level of precision in daily operations, nor do they directly impact the control of biological treatment processes in the same way that a DO meter does.