Menu Close


As a natural continuation of more than 25 years of successful commitment in the field of measurement of noise and vibrations, SPECTRI Ltd. has launched its new laboratory for testing and calibration of noise meters, sound calibrators, personal noise dosimeters: SPECTRI - LAB.

On April 30, 2019, SPECTRI Ltd. received an accreditation certificate, according to the standard BDS EN ISO / IEC 17025 issued by EA "BAS", with a unique registration number LIC № 1 of the testing and calibration laboratory "SPECTRI - LAB" .

With this initiative, SPECTRI Ltd. aims to strengthen its portfolio of services in the field of measurement, evaluation and calibration, to increase its expert potential and provide its customers with professional support in their tasks of meteorological assurance and quality control of their use. equipment.

SPECTRI Ltd., through its testing and calibration laboratory SPECTRI Lab, provides a new type of services on the Bulgarian market, namely:


SPECTRI Lab performs environmental noise testing: 

  • 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 equipment:  

  • Sound level meters 
  • Acoustic calibrators
  • Multi-functional acoustic calibrators
  • Noise dosemeters

The Brüel & Kjær 3630 Calibration Platform is a versatile platform for calibration of instruments and transducers in the field 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.

Calibration Form

If you would like to request a calibration, please fill in the form below. We will contact you as soon as possible.

If you do not represent a company or institution, please leave the field blank.
What kind of device would you like us to calibrate for you?
At what email address can we contact you?
To which address should we return the calibrated device by courier? (You can also personally pick up the calibrated device from our office: Sofia 1700, Studentski Complex, Baku Street № 5A, floor №5, office 5-2,3)
When (or by what date) would you like the calibration to be performed? If you are unsure, leave blank.
Is there anything else you would like to tell us concerning this calibration?
SPECTRI accepts ONLY bank payments.
en_GBEnglish (UK)