Previous step

Select the product you are interested in (1)

Next step
  • ADAS
  • Brake Test
    Brake Test
  • Combustion Analysis
    Combustion Analysis
  • E-Mobility
  • Harsh Environment Testing
    Harsh Environment Testing
  • Pass-by Noise
    Pass-by Noise
  • Road Load Data
    Road Load Data
  • Vehicle Dynamics
    Vehicle Dynamics
  • Power Analyzer
    Power Analyzer
  • Power Quality
    Power Quality
  • E-Mobility
  • FFT Analyzer
    FFT Analyzer
  • Order Tracking
    Order Tracking
  • Octave Analysis
    Octave Analysis
  • Balancing
  • Rotational and Torsional Vibrations
    Rotational and Torsional Vibrations
  • Human Body Vibration
    Human Body Vibration
  • FFT Analysis
    FFT Analysis
  • Modal Analysis
    Modal Analysis
  • Shock Response Spectrum - SRS
    Shock Response Spectrum - SRS
  • Fatigue Analysis
    Fatigue Analysis
  • Sound Level Meter
    Sound Level Meter
  • Octave Band Analysis
    Octave Band Analysis
  • Sound Intensity
    Sound Intensity
  • Sound Power
    Sound Power
  • Reverberation Time RT60
    Reverberation Time RT60
  • PCM Telemetry
    PCM Telemetry
Thanks for contacting us. One of our specialists will get in touch as soon as possible.

Sound Level Meter

The sound level meter solution from Dewesoft allows calculation of the specific parameters typically found in standard sound level meters for sound level measurements utilizing either single or multiple microphones. The Dewesoft solution can be used as a Class I sound level meter.

Sound pressure
Sound pressure

Main Features

  • CLASS I SOUND LEVEL METER: Use DEWESoft as Class I sound level meter (IEC 61672)
  • REAL-TIME SOUND ANALYSIS:  perform real-time sound measurement and analysis
  • MICROPHONE CALIBRATION: calibrate a microphone with TEDS chip, calibrator or a calibration sheet
  • FREQUENCY WEIGHTING:  Standard frequency weighting curves: A, B, C, D, and Z(linear) and time weightings (Fast, Slow, and Impulse)
  • CALCULATED OUTPUT CHANNELS: SPL, equivalent sound pressure level, sound energy, impulsivity of sound, ....
  • STATISTICAL NOISE LEVELS: LAF1, 5, 10, 50, 90, 95 and 99 % classes of values
  • DIRECT MICROPHONE INPUT: the Dewesoft data acquisition hardware allows direct input of IEPE compatible microphones with TEDS support for automatic configuration. Data acquisition system can be configured for any number of microphone inputs.

Class 1 Sound Level Meter

Class 1 sound level meter is designed to meet the requirements of IEC 61672. This standard specifies two levels of performance, Class 1 and Class 2, with Class 1 being effectively more accurate.

Within the standard are a set of performance criteria that an instrument must meet and each of these has a tolerance associated with it.

Real-time Sound Analysis

Real-time octave and third-octave filters analyze a signal and measure energy at the output to give frequency data. The  Octave Analysis option provides time-based realtime octave band and 1/3 octave band measurements. Additionally, 1/n octaves can be post processed for requirements that need 1/6 octave, 1/12 octave, and 1/24 octave band spectral analysis.

Microphone Calibration

In order to make a scientific measurement with a microphone, we must know its precise sensitivity. Microphone calibration will enable confidence in the performed measurements. Since this may change over the lifetime of the device, it is necessary to regularly calibrate the measurement microphone. A microphone can be calibrated into several different ways in DEWESoft:

  • with TEDS  (the sensitivity of the microphone is written on TEDS chip, the software will read it)
  • with a calibrator (calibrate the microphone with the calibrator directly in DEWESoft)
  • with calibration certificate (simply enter the sensitivity into the channel setup of the microphone)

Frequency Weighting

Frequency weighted noise measurements offer convenient ways to measure sound, and we use each of these frequency weightings for different types of measurements.

  • A-weighting is applied to measured sound levels in an effort to account for the relative loudness perceived by the human ear. The human ear is less sensitive to low and high audio frequencies.
  • B-weighting is the best weighting to use for music listening purposes.
  • C-weighting is used for high-level noise measurements.
  • D-weighting was specifically designed for use when measuring high-level aircraft noise in accordance with the IEC 537 measurement standard. The large peak in the D-weighting curve reflects the fact that humans hear random noise differently from pure tones, an effect that is particularly pronounced around 6 kHz.
  • Z-weighting is linear at all frequencies and it has the same effect on all measured values.


Time Weighting

Sound level measurements using any grade of a sound level meter can be fast, slow, or impulse time-weighted. These weightings date back to the time when sound level meters had analog meters and defined the speed at which the meter moved.

  • Fast - the needle would move fast to show quickly varying noise. Fast corresponds to a 125 ms time constant.
  • Slow - the needle would be damped to smooth the noise out to be easier to read. Slow corresponds to a 1-second time constant.
  • Impulse - The Impulse time weighting is about four times faster than Fast, with a short rising time constant but a slow falling constant. Impulse has a rise time constant of 35 ms and fall time constant of 1,5 s.


Calculated Parameters

Sound level meter calculates several parameters and channels in real time, during the measurement:

  • Lp (SPL) - time and frequency-weighted sound pressure level (SPL) already scaled to dB (decibel) 
  • Lpk value, which shows the current maximum value of the sound levels
  • Frequency weighted raw value shows the frequency weighted time curve of sound in Pa (Pascal).
  • frequency-weighted Leq value, which is equivalent continuous sound level
  • Lim tells the impulsivity of sound and is the impulse-weighted equivalent
  • LE which is the frequency-weighted sound energy

True Peak Level

True peak level shows the real peak value of the input signal in dB. The sound pressure level always contains a time weighting filter, which has an influence on the peak value.

 The SPL does not reach that high values, no matter if we select F, S or I time weighting. The LCpk, however, shows the “true peak”. 

Free Online Training

You can learn more about sound level measurement at Dewesoft PRO online training by navigating to the Sound Level Meter PRO training course.

Dewesoft PRO training is a free online training for measurement professionals. Learn how to measure signals, data processing and how to use Dewesoft products. Online PRO training is completely free. 

Related products