When choosing a professional ear thermometer calibration service, it is necessary to check the qualification certification of the service agency. Agencies with authoritative metrology certification qualifications are more reliable. At the same time, it is also important to understand the advanced level of their calibration equipment and the professional level of the calibration personnel. Professional calibration personnel should be familiar with the working principle and calibration process of the ear thermometer and be able to accurately handle problems that occur during the calibration process. In addition, other users' evaluations and reputations can also be referred to for selection.