What should be done to maintain accuracy in sample results?

To maintain accuracy in sample results, conducting constant maintenance is essential. This includes ensuring that all equipment and instruments used in the sampling process are properly calibrated and functioning as intended. Regular maintenance helps to prevent issues that could arise from equipment malfunctions or inaccuracies, ensuring that samples are collected and analyzed under the best possible conditions.

Additionally, maintaining the areas where samples are taken can minimize contamination and other external factors that may affect the quality of the samples. Constant diligence in maintenance practices supports consistent and reliable results, which is crucial in wastewater treatment processes.

The other options, while they focus on different aspects of sampling, do not contribute to maintaining accuracy in the same comprehensive manner. For instance, limiting sampling frequency may reduce the amount of data collected, which can lead to skewed results. Utilizing only fresh samples ensures quality but does not address potential inaccuracies from equipment or methods. Storing samples in sunlight is counterproductive, as exposure to light can compromise the integrity of many samples. Thus, ongoing maintenance stands out as the most effective approach for ensuring accurate sampling results.