Description

Noise, vibration, and harshness test equipment is equipment used to test and monitor noise, vibration, and harshness in mechanical and electrical systems.

Noise, Vibration, and Harshness

Noise, vibration, and harshness are three ways to describe environmental disturbances that have an impact on both people and systems.

• Noise is unwanted sound or unwanted disturbance in an electronic signal. Acoustic noise is energy transmitted to the air that causes audible disturbance. Tools such as acoustic intensity mapping and combustion/mechanical noise separation can be used to identify the best method of noise reduction.
• Vibration is oscillation that causes noise and disturbance. Vibration is generally of concern due to the physical effects which can cause disturbance to people, disruption in electrical systems, and failure or breakdown in mechanical systems. Shakers and controllers are techniques used to test vibration issues.
• Harshness is generally used to describe the severity and discomfort associated with both vibration and noise. It is a qualitative system based on desired characteristics rather than on quantifiable measurements.

Types

There are various types of equipment used in the testing of noise, vibration, and harshness.

• Analyzers are electronic devices which can quantify and assess noise and vibration. Many of these devices are portable.
• Shakers and controllers provide signal analysis and control of vibrational noise. Shakers can be built for a range of different vibrational forces from small (25lb_f) to very large (1000lb_f).
• Noise dosimeters are specialized sound level meters intended to measure exposure of a person to noise over time.
• Electromagnetic acoustic transducers (EMATs) are transducers for non-contact sound generation and reception using electromagnetic mechanisms.
• Dynamometers measure force, moment of force, or power. In the case of NHV testing, dynamometers simulate motors and other mechanical devices to test vibration and noise characteristics.
• Sound level meters are devices used to measure sound pressure levels. They are used for quantification of almost any noise in noise pollution studies.
• Microphones are recording devices that can be used to test noise and sound levels from most sources.
• Analysis software includes all computer programs and tools that provide interface and allow manipulation of outputs from recorded and testing devices.

Applications

NHV test equipment is used in a number of industries and practices. One of the primary industries is the automotive industry, which tests the vibration and noise output from vehicle engines and motors. NHV equipment is also used to set and test noise pollution standards in work environments for occupational health and safety practices.