Unlike most process measurements, the measurement of a rotating machine’s vibration is primarily for the benefit of the process equipment rather than the process itself. Vibration monitoring on an ammonia vapor compressor, for instance, may very well be useful in extending the operating life of the compressor, but it offers little benefit to the control of the ammonia vapor.

Nevertheless, the prevalence of machine vibration measurement technology is so widespread in the process industries that it cannot be overlooked by the instrument technician. Rotating machinery equipped with vibration sensors is often controlled by protection equipment designed to automatically shut down the machine in the event of excessive vibration. The configuration and maintenance of this protective equipment, and the sensors feeding vibration data to it, are often the domain of instrument technicians.

We will discuss the below topics in the next chapter:
- Vibration physics( Sinusoidal and Non-sinusoidal)
- Vibration sensors
- Monitoring hardware
- Mechanical vibration switches