NVH Tools of the Month

By DE Editors

From the annoying squeak in a car’s dashboard to the loudness of a dishwasher, noise, vibration and harshness (NVH) testing is a critical step in many engineering processes. Products must meet consumer demand for quiet operation as well as, in many cases, government regulations to prevent noise pollution.

“There are national noise control laws in every country and government agencies have defined ‘acceptable’ noise level ranges for various sources of noise,” according to a market report by Frost & Sullivan, an industry research and consulting firm.

At presstime, the firm was planning to release an update of its “World NVH Test Equipment Market” report. It says government regulations and new technologies—such as electric vehicles and the trend toward portable consumer electronics—are driving growth in the NVH test equipment market.

A number of products are available to help engineers acquire NVH data from sensors, condition that data via filtering and/or amplification, and pass it to a workstation via data acquisition hardware. Once collected, the data can be analyzed by specialized NVH software. The products listed here can help you measure and correct NVH so you can meet regulatory and consumer requirements for quiet operation of the prototypes you design and test.

Sound Probe Interfaces with IEPE Input Devices
G.R.A.S Sound and Vibration has released the 50GI sound intensity probe for direct connection to signal analyzers or data acqusition devices with IEPE inputs. The probe includes a pair of phase-matched prepolarized precision microphones, which the company says meet the requirements in IEC standard 61043* for a class-1 intensity probe. The-in. CCP preamplifiers are designed to ensure minimum disturbances to the sound field for accurate measurements in the full frequency range.

Microflown Releases Scout 422 DAQ
The Scout 422 is a 24-bit resolution USB data acquisition device from Microflown Technologies. It is developed for noise and vibration measurements with   Microflown probe based solutions. The Scout 422 has four inputs, one output, an amplified output, tacho input and a external trigger channel. It also supports other sensors like microphones, accelerometers, IEPE sensors and tachometers.
 
NI Releases Sound and Vibration Measurement Suite 2011

National Instruments has announced the latest version of its NI Sound and Vibration Measurement Suite software, which provides a collection of analysis and signal processing tools for noise, vibration and harshness (NVH) testing, machine condition monitoring (MCM) and audio test applications. Engineers can use the suite as stand-alone software or combine it with NI hardware and NI LabVIEW system design software to help simplify test system development and control. With its new vibration data-logging functionality and other enhancements, the Sound and Vibration Measurement Suite 2011 is said to help engineers more easily customize and automate any MCM or NVH test or monitoring application.

Accelerometer Kits Designed for Gas Turbines
IMI Sensors, a division of PCB Piezotronics, Inc., (pcb.com) has launched the 600B13/B14 high temperature accelerometer kits for vibration measurement in gas turbines. These kits include a side-exit charge mode sensor, 10-ft. integral hermetically sealed hard-line cable, and integral ICP charge amplifier for multiple power generation monitoring applications, including placement on turbines, exhaust systems, and piping in extreme heat environments of +900 °F/+482 °C.

Measure Sound from 35 to 130 dB
Omega Engineering’s Handheld Sound Level Meter has an electret condenser microphone with a Lo range of 35 to 90 dB and a Hi range of 75 to 130 dB. The handheld device has a liquid crystal display with a maximum reading of 1999, an accuracy of +/- 1.5 dB and a dynamic range of 55 dB. It features a maximum hold function, slow and fast frequency weighting and AC and DC output functions.

Data Acquisition and Process Monitoring Software
Coda is m+p international’s new software platform for measurement, data acquisition, signal analysis and process monitoring. According to the company, it provides quicker time to test by eliminating costly application programming and long learning curves through out-of-the box functionality. High-channel count applications using hundreds   of channels can be configured within a short time, according to the company, and are handled safely and efficiently. Coda supports a range of VXIbus and LXIbus frontends.

Signal.X Technologies Announces MajX Shield
Signal.X Technologies’  MajX Shield helps engineers design and deploy NVH metrics for use in machine condition monitoring (MCM) applications, automated production NVH tests, and laboratory test stand automation. Metric formulations developed in Shield are deployed using the company’s MajX NVH Controller, which operates at the direction of a test stand control system. The MajX Data Manager retrieves data produced by one or more NVH controllers and can schedule delivery of automated reports based on storable database queries and   “what if” metric calculations.

PULSE 16 Analyzer Released

PULSE is Bruel & Kj r’s platform for noise and vibration analysis. The platform consists of PULSE Reflex, Acoustics and Structural Dynamics components. New functionality includes a module for the Desktop NVH Simulator suite used for auralising the exterior sound that would be experienced by a pedestrian, updates to the latest required standards such as ISO 3744 and IEC 60704-2-4, and the ability to listen to your SPC results, turn paths on and off, listen over a time or RPM range, compare different sets of results back-to-back or apply filters. Engineers can create “what-if” scenarios, and listen to what the product could sound like if certain modifications were made.