What does a tachometer measure in relation to pumps?

A tachometer is a device specifically designed to measure the rotational speed of an object, typically expressed in revolutions per minute (RPM). In the context of pumps, understanding the speed of rotation is crucial as it directly impacts the pump's performance and efficiency.

For pumps, maintaining the correct RPM is vital for ensuring that desired flow rates and pressures are achieved. Operational parameters, such as cavitation and power consumption, can also be affected by the speed at which the pump operates. Therefore, monitoring RPM helps operators in troubleshooting and optimizing pump performance for various applications.

In terms of the other options, while torque, pressure, and flow volume are all important parameters in the operation of pumps, they are measured by different types of instruments designed specifically for those tasks. A torque measurement device provides information about power output, pressure gauges measure the pressure of the fluid, and flow meters assess the volume of fluid moving through a system. Each of these plays a role in overall pump operation, but they do not provide the rotational speed measurement that is the primary function of a tachometer.