What indicates that a dissolved oxygen (D.O.) meter membrane requires attention?

A D.O. meter measures the amount of dissolved oxygen in the water, which is crucial for assessing water quality in wastewater treatment processes. If the meter's needle fluctuates, it suggests that the membrane of the probe is either damaged or contaminated. A stable reading is essential for accurate measurements; fluctuations can indicate that the sensor is not functioning correctly, potentially leading to erroneous data.

In contrast, error codes displayed on the meter point to various underlying issues that may not be specific to the membrane, while consistent readings typically suggest that the membrane is working properly. Correct calibration means that readings are aligned with known standards, but it does not provide information about the health of the membrane. Thus, observing needle fluctuations serves as an important sign that the membrane needs attention to ensure reliable measurements.