In addition to measuring reverberation time, the evaluation of reverberation room should also test the conformity of diffusion field conditions in the room. Generally, more than 6 measurement points are selected in the acoustic field. The measurement point interval should be larger than normal /2, and the standard deviation of measured sound pressure level should be less than + / - 1dB. There should be vibration isolation between the reverberation chamber and the base to reduce background noise.
Reverberation rooms are designed for the determination of sound power output of noise sources, transmission loss of partitions, insertion loss of silencers, response characteristics of microphones and random incidence absorption coefficients of materials. They are also used for high-intensity noise-level fatigue testing of aircraft,space vehicles and other equipment.
The purpose of a reverberation room is to create a highly diffused acoustic measurement environment, defined as a sound field in which acoustic energy flows equally in all directions.
A reverberation room must provide sound isolation against extraneous noises and an environment which can be temperature, pressure and humidity controlled.DP Acoustics has installed many field-proven reverberation rooms in different configurations. With more than 60 years experience, DP is the pioneer and leading company in the design, construction and commissioning of modular reverberation chambers.
Construction of Reverberation Rooms
For a reverberation room to perform correctly, careful consideration must be given to a number of factors which include:
? Test standard or method
? Interior volume
? Room dimensions in relation to test object size
? Interior working space
? Lowest frequency band of interest
? Internal acoustic ambient noise level
? Noise reduction
? Vibration isolation
? Silenced ventilation systems
? Doors and access
? Lighting and electrical systems
? Overall structural requirements
Standard Features DP reverberation rooms come fully equipped with the following features:
? DP Hardliner? panel construction
? Double / single wall and ceiling construction
? DP ventilation system coupled to building supply
? Interior lighting and power
? A standard size DP Noise-lock ? acoustic door
? Complete certification and commissioning tests
Options
? Self-contained air handling/ ventilation system
? Additional/larger door
? Access panels for equipment and test openings
? Air mounts, or other types of vibration isolation
? RF shielding
? Turning vanes and/or diffusers
DP Ventilation Systems
A ventilation system must provide adequate air circulation at sound pressure levels below design criterion. DP Quiet-vent ? silencing systems are designed to provide approximately 15 air changes per hour in a typical anechoic facility. If specialist heating/cooling needs are required, then IAC Acoustics can custom-design a system to meet your needs. DP Acoustics is an industry leader in the design and construction of silencing devices for air/gas flow systems. These range from minimal air changes to large elaborate intake and exhaust silencing systems to accommodate engine research within an acoustic test facility. DP has designed and manufactured hundreds of thousands of silencers for soundproof rooms, HVAC systems, industrial machinery, power plants, engine test cells and gas turbines.
Ancillary Equipment
In addition to core acoustic products, DP Acoustics is also able to offer full integration of other ancillary equipment within facilities, including electrical items (lighting, alarms, sensors, CCTV etc) and mechanical plant and equipment (chassis dynamometer, instrumentation, chillers etc).
Lighting
DP supplies the latest LED-based lighting system that is designed to provide a diffused light field. IAC also include emergency lighting as necessary. The lighting provided ensures that horizontal luminance in the working area at 1m above the floor is no less than 600lux and their lifespan rated at no less than 75,000 hours. The lights are selected to achieve the lowest possible background noise levels and ambient temperatures.
