When calibrating a torque wrench, what important step should the technician always take before calibration?

Before calibrating a torque wrench, exercising the unit under test is an essential step. This process involves applying torque to the wrench multiple times across its range, typically by tightening and loosening a fastener. The objective of this exercise is to ensure that the mechanical components of the torque wrench, such as the internal springs, are fully engaged and settled into their operational positions. This helps in achieving consistent and accurate readings during the actual calibration process.

When a torque wrench is properly exercised, it reduces the likelihood of any residual effects from previous use or mechanical stiffness affecting the calibration results. Additionally, exercising the tool helps to simulate typical usage conditions, ensuring that the calibration reflects real-world performance. This foundational step is crucial because an improperly exercised wrench could deliver inaccurate torque measurements, ultimately compromising the reliability of the wrench when it is used in applications.

The other options, while they may have their own relevance in various contexts, do not address this critical preparatory step before the calibration takes place.