What is a tachometer and what does it show?

What is a tachometer and what does it show?

• A. Tachometer displays engine speed in revolutions per minute; RPM required to pump rated capacity is determined and recorded on an identification plate on the pump panel during acceptance testing; wear may indicate pump issues.
• B. Tachometer measures fuel efficiency.
• C. Tachometer shows engine temperature.
• D. Tachometer measures oil pressure.

Answer: (A)

A tachometer shows engine speed in revolutions per minute. In a fire pumper, the engine’s RPM is tied to the pump’s ability to deliver rated capacity, so technicians determine the RPM required to meet that capacity and record it on the pump panel’s identification plate during acceptance testing. The tachometer lets you monitor that speed in real time, and wear or mechanical issues in the pump or drive system can cause changes in engine speed under load, signaling potential problems. This instrument doesn’t measure fuel efficiency, engine temperature, or oil pressure—those functions are handled by other gauges.

A tachometer shows engine speed in revolutions per minute. In a fire pumper, the engine’s RPM is tied to the pump’s ability to deliver rated capacity, so technicians determine the RPM required to meet that capacity and record it on the pump panel’s identification plate during acceptance testing. The tachometer lets you monitor that speed in real time, and wear or mechanical issues in the pump or drive system can cause changes in engine speed under load, signaling potential problems. This instrument doesn’t measure fuel efficiency, engine temperature, or oil pressure—those functions are handled by other gauges.