OFFICE: 1700 - Sofia, Student Complex, 5A Baku Street, office 5-2,3

Phones: (+359 2) 963-0464, 963-2638
Fax: (+359 2) 963-1074



As a natural continuation of more than 20 years of successful commitment in the field of measurement of noise and vibrations, SPECTRI Ltd. (Manager – M. Sc. Eng. Boris Mihaylov) has launched its new Laboratory for testing and calibration of noise meters, sound calibrators, personal noise dosimeters, SPECTRI - LAB.

The company is investing in the latest generation of measuring and software equipment from the world's highest class manufacturers (Brūel&Kjær) to provide its Bulgarian partners and customers with a reliable, fast and flexible service to support their ambition to work accurately and deliver quality business.

As of 2016 SPECTRI Ltd. has started a process of accreditation of a test and calibration laboratory for environmental noise testing and for calibration of noise meters, sound calibrators, and personal noise dosimeters according to the standard BDS EN ISO / IEC 17025:2016 - Laboratory for testing and calibration SPECTRI - LAB.




ORDER № A 159/30.04.2019


SPECTRI Ltd., using a testing and calibration laboratory, SPECTRI-LAB offers a new type of services on the Bulgarian market, namely:


SPECTRI - LAB performs noise testing in the environment:

  • Equivalent noise level (Equivalent sound pressure level), dB (A)
  • Maximum - weighted noise level A (Maximum A - weighted sound pressure level), dB (A)
  • Impact noise level, dB (A)
  • Sound power level, dB (A)

SPECTRI - LAB calibrates the following instruments:

  • Calibration of sound level meters
  • Calibration of acoustic calibrators
  • Calibration of multifunctional acoustic calibration
  • Calibration of noise dosimeters


The Brüel & Kjær 3630 Calibration Platform is a versatile platform for calibration of instruments and transducers in the fields of noise and vibration. The Brüel & Kjær 3630 calibration platform uses the portable 100 kHz PULSE ™ analyzer as a core part of the system.


The applications used by SPECTRI are the following:

  • Sound Meter Calibration (SLM) - Type 7763 Calibration Software - Sound Meter Calibration (SLM) with Type 7763 calibration software is not just an effective tool; in fact, it is a world-class system, easy to recalibrate and with uncertainty budgets needed for accreditation purposes. It is used for acoustic and electronic calibration of sound meters, calibrators, dosimeters, octave filters - according to international standards.


  • Dosimeter Calibration - Type 7792 Calibration Software - NDM Noise Calibration (NDM) with Type 7792 Calibration Software is an automatic tool designed to perform periodic noise dosimeter tests. The system includes a database of current types of calibrated noise dosimeters, including sound level measurement and noise exposure. Uncertainty budgets are provided to facilitate laboratory accreditation (ISO 17025).


  • An instrument for performing automated periodic calibration tests in accordance with IEC 60942 - Type 7794 calibration software for calibrators - Calibrating calibrators with Type 7794 calibration software is a tool for performing automated periodic calibration tests. The system performs calibration of single frequency (250 Hz / 1000 Hz) calibrators and pistons, as well as multi-function calibrators (with different calibration frequencies and amplitudes). Calibration procedures for acoustic calibrators are predefined in the software, with the possibility of adding new types of calibration tools and procedures.


Check out our new brochure -  TCL "SPECTRI - LAB"