How often should a reference thermometer be recalibrated or replaced?

A reference thermometer typically should be recalibrated or replaced every 5 years to ensure accurate measurements in a laboratory setting. This frequency is designed to maintain the quality of the measurements made in drinking water analysis, as thermometers can drift out of calibration over time due to usage, environmental factors, and the inherent properties of the materials used in their construction.

Regular calibration is crucial for the reliability of lab data, affecting the testing of water quality and compliance with safety regulations. A 5-year interval strikes a balance between ensuring accuracy and not being overly burdensome on laboratory operations. This timeframe allows for thorough performance checks without needing constant recalibration, which can disrupt workflow and increase costs.

While other options present shorter or longer intervals, 5 years is the generally accepted best practice in the field for maintaining the integrity of thermometric measurements in laboratories concerned with drinking water quality.