What does a tachometer indicate about the motor of a pump?

A tachometer is an instrument specifically designed to measure the rotational speed of an object, typically expressed in revolutions per minute (RPM). In the context of a motor driving a pump, the tachometer gives crucial information about how fast the motor is operating, which directly impacts the performance of the pump.

Monitoring the speed of the motor allows operators to ensure that it is functioning within its designed parameters, which is essential for the efficient operation of the pump. Proper speed is vital to achieving the desired flow rates and maintaining system stability.

In contrast, the other options relate to different aspects of motor and pump operation. For instance, temperature measurement pertains to motor overheating issues, pressure readings involve the hydraulic system's performance, and operational status controls are related to whether the motor is on or off, none of which are functions of a tachometer. Thus, the primary role of a tachometer is to provide speed readings, confirming that it accurately reflects the motor's RPM.