What is the primary function of the temperature gauge on the outside of the distributor truck?

The primary function of the temperature gauge on the outside of the distributor truck is to ensure proper application temperatures. Maintaining the correct temperature is crucial in asphalt applications because it directly affects the viscosity and workability of the asphalt material. If the temperature is too low, the asphalt may become too thick and difficult to spread, leading to uneven application and poor bonding. Conversely, if the temperature is too high, it can result in a loss of essential oils from the asphalt, making it less effective when applied.

Monitoring this gauge allows operators to make real-time adjustments to maintain optimal temperatures, ensuring that the asphalt is applied correctly and that the end product meets quality standards. Other functions mentioned in the choices, such as maintaining fuel efficiency or tracking vehicle speed, do not relate to the specific role of the temperature gauge in the context of asphalt distribution.