Capabilities

LABORATORY CAPABILITY FOR ACOUSTICS AND VIBRATIONS

1. Acoustic measurements - Testing

• Measurements and recording
  
  - Frequency range: 0.1 Hz -140 kHz
  - Dynamic range: 10 dB - 180 dB
  
  
• Signal - Noise Analysis
  
  - Frequency range: 1 octave, 1/3 octave, 3%, 23%, constant range (3,16 Hz, 10 Hz, 31,6 Hz, 100Hz), narrow 0.25% (0 - 20 kHz)
  - Frequency range: 0.2 Hz - 160 kHz
  
  
• Check of standard conditions:
  
  - Industrial noise measurements (machines and equipment)
  - Urban noise measurements
  - Airport noise measurements
  
  
• Determination of acoustic characteristics of structures
  
  - Absorbing coefficient
  - Acoustic radiation
  - Isolation capacity at air flight noise
  - Isolation capacity at impact noise
  
  
• Quality of audition halls
  
  - Measuring of reverberation time
  
  
• Determination of sound power (ISO 3740 - ISO 3747)
  
  
• Determination of clearness and quality of conversation
  
  

• Absorption of industrial noise (air/steam discharge silencers made by COMOTI , housings)
  
  
• Absorption of industrial and district noise (noise absorbing for buildings)
  
  
• Absorption of traffic noise
  
  

• Measurements and recordings
  
  - Frequency range: 1 Hz - 60 000 Hz
  - Dynamic field: 0 - 5 000 g
  
  
• Analysis of signal vibrations
  
  - Frequency field: 1 octave, 1/3 octave (2 Hz -160 kHz); constant percentage 3%, 23% (0 - 20 kHz); narrow range 0.25% (0 - 20 kHz)
  - Dynamic field: 0 - 5 000 g
  
  
• Mechanic tests for vibrations
  
  - Frequency : 5 Hz - 5 000 Hz
  - Max. load: 50 kg
  
  
• Determination of equipment condition
  
  
• Reaction in frequency of the vibration transducers
  
  - Max. mass: 300 gr
  - Frequency range: 5Hz - 2 000 Hz
  - Max. acceleration: 115 m/s2
  
  

• Vibration absorption for machinery and industrial equipment
  
  
• Vibration absorption for transport means
  
  

I. CHARACTERISTICS OF ANECHOIC ROOM (DEAF CHAMBER)

The anechoic room was designed and builds in accordance with the ISO 3745 requirements.

Characteristics:

• Volume : 1200 m3 (15x10x8 m)
  
  
• Sound absorbing coefficient of walls: α ≥ 99% in the range of 150 Hz - 20 000 Hz.
  
  
• Variation of non-uniformity of field according to distance:
  
  L ± 0.5 dB for d<2 m
  L ± 1 dB for d=3 m
  L ± 1.5 dB for d=4 m
  L ± 2 dB for d=5 m
  L ± 3 dB for d=7.5
  
  L=sound pressure level;
  d=distance from source to measuring point;
  
  
• Background noise is in the curve of Cz 25
  
  
• Sound sources can be measured at a max. Volume of 6 m3
  
  
• The access door in this facility is very large (3,5 x3 m)
  
  

II. CHARACTERISTICS OF THE REVERBERATION ROOM

It was built in accordance with ISO 3741- Annex D ISO 354.

Characteristics:

• Volume: 202.4 m 3 (4,7x5,9x7,3 m, average)
  
  
• Background noise is in the curve of Cz 25
  
  
• Measuring frequency range is determined by enclosure volume:
  
  - lowest frequency in the range of 1 octave - 125 Hz
  - lowest frequency in the range of 1/3 octave - 100 Hz
  
  
• Max. Volume of sound source that can be measured is of 2 m3 (less than 1% of enclosure volume).

III. CHARACTERISTICS OF THE UNIT FOR ACOUSTIC TRANSMISSION MEASUREMENTS THROUGH BULKHEADS

The unit for acoustic transmission through bulkheads was made in accordance with the following international and national Standards: ISO 140/1, /7, /8, STAS 6161/4, STAS 6691.

It consists of:

• 1. A set-up for measuring the absorption of air flight noise in diffuse field, consisting of horizontally adjoining reverberation enclosures, having 106 m3 each (3,7x4x6,1m), a transmitting one and a receiving one. A 10 m2 separating window allows equipment installation.
  
  
• 2. A set-up for impact noise absorbing, consisting of vertically adjoining enclosures, a transmitting one above and a receiving one below, separated by a 10 m2 window that allows the installation of the testing platforms.
  
  

SERVICES (according with the actual standards):

• Measurements and records;
  
  
• Signal analysis - noise;
  
  
• Noise measurements for industrial installations (machinery and aggregate);
  
  
• Noise measurements for urban traffic;
  
  
• Noise measurements for airports;
  
  
• Noise mapping;
  
  
• Measure the acoustic characteristics of structures;
  
  
• Audition hall quality;
  
  
• Measurements of sound power (ISO 3740 - ISO 3747);
  
  
• Measurements for the conversation intelligibility and quality;
  
  
• Industrial sound attenuator (damper for air/vapors, designed by Comoti, carcass, machinery and equipment);
  
  
• Reduces civil and industrial sound (sound damping for insides and buildings);
  
  
• Reduces noise of the transportation means;
  
  
• Vibration signal analysis;
  
  
• Mechanical test for vibrations measurements;
  
  
• Vibration diagnostic of the aggregate stage;
  
  
• Response frequency of the vibration transducers;
  
  
• Vibration amortization of machine and industrial equipment;
  
  
• Vibration amortization of transportation means;