Check whether the appearance of the constant temperature oil bath is intact, without obvious damage or deformation.

Ensure that the heating system, temperature control system, and stirring device of the oil bath can work normally. Check whether the heating element is damaged, whether the display screen of the temperature controller is clear, and whether the keys are sensitive.

Check whether the heat transfer oil in the oil bath is sufficient, and the liquid level should be within the appropriate range. If the heat transfer oil is insufficient, it is necessary to add the appropriate type of heat transfer oil in time.

According to the accuracy requirements of calibration, select a standard thermometer with an appropriate range and accuracy level. For example, for calibration with general accuracy requirements, a standard mercury thermometer or a high-precision electronic thermometer with a resolution of 0.1℃ and a range covering the working temperature range of the constant temperature oil bath can be selected.

Before using the standard thermometer, it is necessary to check its calibration certificate to ensure that the thermometer is within the validity period and the accuracy meets the requirements. At the same time, conduct an appearance inspection of the thermometer, and there should be no damage and the scale should be clear.

The calibration work should be carried out under stable environmental conditions. The ambient temperature should be kept as constant as possible to avoid the influence of temperature fluctuations on the calibration results. Generally, it is required that the difference between the ambient temperature and the set temperature of the constant temperature oil bath does not exceed ±5℃.

There should be no obvious vibration and electromagnetic interference in the workplace to ensure the normal operation of the equipment and the accuracy of the measurement data during the calibration process.