Acoustics Lab

Mission

Technicon Acoustics is a full service noise and vibration solution provider. Our talented, experienced personnel will take you through Technicon Acoustics proven methodology of creating the most cost effective noise and vibration control solution.

Contact

John Gagliardi regarding your noise and vibration concerns:

John C. Gagliardi, Ph.D.
Technical Director
Phone: 704-788-1131 X 3029
Fax: 704-788-7772
E-mail: jgagliardi@techniconacoustics.com

Overview

The Technicon Solution encompasses:

Initial consultation
Needs, goals and targets determination
Quantification of problem
Solution investigation
Production and delivery of solution
Service

Technicon is based on accountability, and organized so one contact can follow through all your concerns and interests. Technicon is also large enough to meet your production needs and time schedule.

Initial Consultation

A teleconference or meeting to familiarize both parties as to each other’s business, products, markets and noise/vibration concerns.
Needs, Goal, Target Determination

Although the source of the problem may not have been clearly identified, the expected performance will most likely have been. A variety of performance goals may exist. Performance goals could be to perform better than ones competitor, meet target noise levels, quieter than the preceding generation of the product, or be less annoying to the equipment operators or bystanders.
Quantification of Problem

From consulting with Technicon’s noise and vibration experts, a testing methodology will be formulated. The testing methodology will be created to take advantage of Technicon advanced noise and vibration instrumentation and experience. A listing of Technicon’s advanced noise and vibration capabilities are provided within.
Solution Investigation

Technicon’s expert staff with years of experience will formulate a number of potential solutions. The solutions are fabricated at Technicon’s facilities. The effectiveness of the solution can be evaluated by your company or Technicon’s Noise and Vibration laboratory.
Production and Delivery

Technicon has the capabilities to meet your company’s schedule and material needs.
Service

Technicon is committed to high levels of customer satisfaction and internal self-improvement. Our staff routinely calls customers to determine if needs are being met with a high level of satisfaction.

Product Noise Control

The Technicon Noise and Vibration Laboratory was designed with the intention of performing diagnosis in the field with the equipment operating in their normal environment. Technicon provides an effective combination of technical expertise, technical capabilities and solution implementation. Technical capabilities to accurately identify noise and vibration concerns in regards to product noise control and sound quality are given below:

Fundamental Analysis

Quantify noise or vibration levels as overall or in frequency bands with common weighting schemes such as linear, A and C and time responses such as slow, fast, impulsive, peak, and EQ.

Transfer Path Analysis

Typically a noise/vibration source will occur at one location, travel a particular path and then be perceived by the person. This is called source-path-receiver studies or transfer path analysis. Many times the source cannot be modified, and hence to block the noise or vibration to the person, the path must be modified. Technicon posses advanced multi-channel analysis capability to determine at a particular location the amount of contribution of each noise and vibration source. This allows one to identify the problem source to focus noise control efforts. Once problem source and paths have been identified, the effectiveness of noise control efforts can be quantified by measuring the reduction in the transfer function between source and receiver.

Multi-channel digital recording

Technicon possesses an 8-channel digital audio tape (DAT) recorder. This allows up to eight channels of simultaneous recordings of operating machinery noise and vibration. The captured vibration and noise can then be analyzed in detail back in the laboratory. An additional benefit is that the sound is permanently recorded to allow subjective listening. The human is the only true judge of how annoying a sound is. The high quality digital recordings will allow subjective ratings of the sounds.

Noise Source Location

Operating machines tend to be complex with many noise sources and paths. Many times it is difficult to isolate one noise source from another with only sound pressure level measurements. This is because sound pressure is a scalar quantity. Scalar meaning that directional information of the sound is absent. An advanced technique that measures the direction sound travels is called sound intensity. A sound intensity probe is used to determine primary sound direction. The sound intensity probe is sensitive to sound coming only from a particular direction. The use of a sound intensity probe makes it much easier to quantify noise coming from only components of interest in complex machinery. Technicon possesses both the specialized sound intensity probes and analysis software to allow one to rank the noise source components. Valuable engineering resources and noise control efforts are only focused on the greatest noise concerns.

Sound Power Measurements

Products such as mining, construction, agricultural, lawn, HVAC and power generation rate their products using the acoustic quantity of sound power. Sound power and sound pressure are two different quantities. Sound power is the total amount of acoustic watts emitted by the equipment. Sound pressure levels are dependent on the acoustic environment the equipment was measured in and where the sound measurements were taken in relationship to the operating machinery. Sound power is a fundamental acoustic characteristic and is independent of the location and distance from operating machinery. Sound power measurements using sound intensity is defined in ISO 9614-1&2 1996. Using Technicon's sound intensity probes, in-situ sound power measurements can be obtained on operating machinery.

Material Acoustic Performance

When a sound wave encounters a different media or material the sound is changed. The sound can be reflected, transmitted, absorbed or diffracted. Roadside barriers or office partitions are good common examples. By absorption, the sound enters the different material and its energy is converted from kinetic (motion) to thermal (heat). Sound may be also transmitted though the material. Measuring the difference in the sound level in the space before encountering the material and then in the space after passing through the material is called the noise reduction (NR). The insertion loss is the difference in the noise level in the receiving space when the blocking material is present and absent.

Normal Incidence Absorption - ASTM E1050

Technicon possess a Spectronic’s Acupro impedance tube to measure normal incidence absorption to ASTM E1050. The analysis software calculates normal incidence absorption coefficient, reflection coefficient, normalized resistive impedance and normalized reactive impedance. The impedance tube can obtain results from 50 Hz to 5000 Hz.
Sound Insulation Noise Reduction and Insertion Loss

Noise Reduction (NR) and Insertion Loss (IL) measurements can be made on small prototype samples at Technicon facility. The NR and IL measurements are obtained by using the Spectronic’s Acupro impedance tube and in-house customize fabrication. Technicon has customized an enlarged test sample holder and receiving chamber. Small prototype and production samples can be evaluated very quickly as to their noise reduction ability for a particular application.
Damping - ASTM E756

Damping is related to the ability to reduce structure borne noise in vibrating surfaces. Vibrating structures compress and expand air that causes sound. Adding damping material to the surface of vibrating structures reduces vibration levels. These materials dissipate the vibration energy as heat. Technicon possess a Bruel & Kjaer 3920 Oberst Bar damping test rig. The B&K 3920 allows measurement of Young’s Modulus and damping loss factor of the composite and damping material and the shear modulus of the damping material. These measurements can be obtained to ASTM E756 test standard. Because the Young’s Modulus and damping loss factor changes with temperature, it is desirable to obtain these measures at a variety of temperatures. Technicon possesses a Cincinnati Subzero (CSZ) Environmental Chamber. The CSZ allows measurement of the damping parameters over the temperature range of -34°C to 190°C (-30°F to 375°F).

Architectural and Environmental Acoustics

Technicon has the capabilities to measure important architectural acoustic measures such as noise criteria (NC), reverberation time (RT60), sound transmission class (STC) and speech interference level (SIL). Technicon also possesses state of the art noise prediction software for HVAC noise and environmental noise.

Noise Criteria - NC

NC is a measure of the steady noise acceptability of a room for its purpose. Acceptable NC values are defined for a particular room’s application. Rooms requiring low noise levels will have small NC values.

Reverberation Time - RT60

Reverberation time is related to how long a noise persists after its sound source is turned off. The formal definition of RT60 is the amount of time required for sound to decrease 60 decibels. Rooms with great RT60 values typically decrease speech intelligibility and are great sources of nuisance for hearing impaired individuals trying to understand speech. Spaces such as gymnasiums, pools, cafeterias typically contain only hard surfaces. Hard surfaces cause sound to be reflected and hence have greater reverberation times.

Sound Transmission Class - STC

STC is an overall rating of building interior floors and walls to block sound from one room from entering another. Field STC measurements are obtained by place a noise source in one room and measuring the amount of sound transferred into an adjacent room. ASTM specifications E336 and E413 define the test procedure and reporting.

Speech Interference Level - SIL

Human speech is primarily contained within the frequency bands of 500 Hz to 4000 Hz. Hence, noise existing within the 500 Hz to 4000 Hz will mask speech resulting in fewer words understood. The SIL is obtained by averaging the noise levels in the octave frequency bands from 500 Hz to 4000 Hz.

Environmental Noise Modeling

Many time industrial facilities such as power plants and factories produce noise that produce high annoyance in adjacent residential neighborhoods or violate local noise ordinances. Environmental noise modeling software allows one to predict noise levels in the adjacent neighborhoods before operation, or with candidate noise control treatments. Technicon possesses environmental noise modeling software to ISO 9613.

HVAC Noise Modeling

Noise caused by HVAC or mechanical equipment can be a large source of annoyance in buildings. Technicon possesses state of the art HVAC/mechanical equipment noise modeling software based on ASHRAE algorithms.

Sound and Vibration Instrumentation

Sound Absorption

ASTM E1050 - Normal Incidence Absorption using Spectronic Acupro impedance tube. Results valid form 50 Hz to 5000 Hz. Absorption coefficient, reflection coefficient, normal active and reactive impedance.

Damping

Bruel & Kjaer 3930R Oberst Bar damping rig for ASTM E756. CSZ environmental chamber with temperature range from -34°C to 190°C (-30°F to 375°F). Measurement of Young's Modulus and damping loss factor of the composite and damping material and the shear modulus of the damping material.

Analyzers

Larson-Davis 2900 portable analyzer

Two channel fractional octave analysis, fft analysis and sound intensity. Two channel analysis such as frequency response function, cross spectrum and coherence. In-situ sound power, reverberation time, and stc. Dynamic machinery analysis such as order tracking and synchronous averaging with tachometer input. Inputs for microphone, accelerometer and line. Battery or line power.

Larson-Davis 3200 portable analyzer

Two channel fractional octave analysis and fft analysis. Two channel analysis such as frequency response function, cross spectrum and coherence. Dynamic machinery analysis such as order tracking and synchronous with tachometer input. Inputs for microphone, accelerometer and line. Battery or line power.

Microphones

Pair of phase matched ½" Larson Davis 2541 microphones for sound intensity analysis. Pair of phase matched ¼" Larson Davis 2520 microphones for sound intensity analysis. Pair of ½" ACO-Pacific high sensitivity, low noise floor 7046 free field microphones Pair of ½" ACO-Pacific high sensitivity, low noise floor 7047 pressure microphones

Vibration

Four PCB Piezotronic low weight model 333B30 with tri-axial mounting block. PCB 086C05 impulse hammer with 2 KHz frequency response. PCB 482A16 four channel ICP power supply.

Sound Intensity and Sound Power

Two Larson-Davis 2250 sound intensity probes.
Sound Intensity and Sound Power resident analysis software in LD 2900 analyzer.

Recording

TEAC RD135, 8 channel Digital Audio Tape (DAT) recorder with LD2204 microphone/ICP/Line input interface.