How should a straight edge be calibrated before use?

Calibrating a straight edge at the beginning of each working period ensures that it is accurate and reliable for measuring surfaces as work proceeds. This practice is essential for maintaining the quality of asphalt paving since even slight inaccuracies in measuring can lead to problems such as improper thickness or uneven surfaces, potentially affecting the longevity and performance of the pavement.

Regular calibration allows for any wear or misalignment that may occur due to handling or environmental factors to be addressed proactively. By establishing a routine calibration process at the start of each working session, crews can be more confident in their measurements throughout the day, resulting in better overall project quality.

The importance of this routine calibration is highlighted by the other options, which do not provide an effective schedule for ensuring accuracy. Calibration at the end of the day may miss issues that arise during the work, while calibrating every hour may be excessive and could lead to unnecessary downtime. Waiting until issues arise is reactive rather than proactive, risking the integrity of the work. Thus, calibrating at the start of each period strikes an ideal balance between diligence and efficiency.