Evaluator Type 7820


7820Windows®-based software for environmental noise evaluation and reporting using data measured with Brüel & Kjær’s sound level meters. Measurement data can be edited and combined in order to calculate a rating level for the noise source in question.

Results are presented according to a framework of user-defined parameters, including time of the day/week as well as penalties for impulse and constant tones. To simplify the assessment, a variety of parameters are available that accord with national standards.


  • Calculation of rating levels according to national and international standards
  • Noise profile measurement:
  • Industrial noise
  • Residential noise
  • Road and rail traffic noise
  • Evaluation of noise in the environment against noise limits according to national and international standards


  • Direct import of data from Sound Level Meter Types 2231 and 2236, 2237, 2238, 2239, and 2260
  • Import of data from Hand-held Analyzer Types 2250 Light, 2250 and 2270 using Measurement Partner BZ-5503
  • Dial-up modem data transfer and remote instrument control of Types 2238 and 2260
  • Tonal Assessment to JNM2-1999, DIN 45 681-1992 and ISO/CD 1996-2-2001-05 using FFT spectra
  • Profile knitting to produce an overall rating level from different time-based contributions
  • Export of data as spreadsheets, text files and copy/paste into other documents

Record sound to document measurements

Using a sound level meter Type 2238 or Type 2260 as a front end, Evaluator can record sound directly onto your PC’s hard drive. Sound recordings are automatically merged into the measurements, marked in the profile display, and can be replayed directly from within this graph.
Evaluator also fully supports Type 2250 and 2270’s on-board sound recording option BZ-7726, i.e. recordings made on the sound level meter will be imported and can be accessed in the same way as those directly made with Evaluator.

Choose your data visualisation

Evaluator can visualise measured data as noise profiles (level versus time), spectra with 1/1-octave and 1/3- octave filters, as FFT spectra, or as statistical displays of cumulative or level distributions – all making it easy to keep an overview and dive into the smallest details.
When viewing FFT spectra, a reference cursor, delta cursor, harmonic cursor and tone cursor is available, and you can overlay one spectrum with another for comparison – a useful feature for machine diagnostics.

Intuitive post-processing

Calculation of the rating level is based on a graphical profile you create from selected measurement contributions. As an example, you can take one measurement file made on-site that contains samples of different noise environments, and use the ‘cut and paste’ functions to build up rating level profiles for each environment, or you take different profile samples and put them together into one long profile.

Marker magic

Marker information is imported with the measurement data, and you can use the wizard to investigate data over a specified time in order to find and mark constant tones based on 1/3-octave measurements, impulse noise, the loudest period, or all data above a certain level. The latter can be used, for example, to locate aircraft fly-over or automotive pass-by events.

Clear and structured rating level calculation

The rating level is calculated using a spreadsheet that you set up to suit the standards you are measuring to. Different times of day can be specified, impulse corrections can be added, constant tone penalties accounted for – in fact all the different aspects of rating level calculations that you find in the most common international standards.


Manufactures Website – www.bksv.com