Where must a temperature indicator be placed when inspecting a roller bearing for a hot box?

The correct placement of a temperature indicator during the inspection of a roller bearing for a hot box is on the lower half of the cup. This is due to the fact that heat typically rises, so the lower half of the cup will provide the most accurate indication of the temperature of the bearing itself. This placement allows for effective monitoring of any overheating issues that could lead to a hot box condition, which may result in bearings seizing or failing if not properly addressed. Monitoring the temperature in this region is crucial for maintaining safe and efficient operations in railway systems, where roller bearings are integral components.