What does a tachometer specifically measure?

A tachometer specifically measures the engine speed, typically expressed in revolutions per minute (RPM). This instrument is crucial for operators as it provides real-time feedback on how fast the engine is running. Understanding engine speed is important for several reasons; it helps ensure that the engine operates within safe limits, allows for better control of vehicle acceleration and performance, and aids in maintaining fuel efficiency.

For fire service vehicle operators, knowing the engine speed can also prevent damage due to over-revving and aids in making informed decisions during operation, such as when to shift gears or when to increase throttle. This is particularly important in emergency situations where precise vehicle control can be critical.