The key components that determines the accuracy of a sound level meter is the measurement microphone and its associated preamplifier. The effectiveness of these components in converting the acoustic signal into an electrical analogue set the maximum accuracy that can be achieved by the ensuing signal processing. Norsonic have a carefully balanced range of measurement microphones to suite a range of applications that complement modern instrumentation yet maintain traditional values.
Norsonic’s range of microphones covers most application and can be used as direct replacement with other brands. Full use has been made of modern materials which when coupled with traditional engineering skills produces microphones that meet all the requirements of the precision measurement standards yet are robust and resistant to corrosion. These microphones are used in conjunction with the Norsonic range of preamplifiers that closely couple to them and ensure perfect matching to the associated instrument with minimum disturbance to the acoustic field. The preamplifiers have the necessary signal handling capability and low self noise to allow full use to be made of the wide dynamic range of the microphones.
Calibration of all Norsonic microphones is directly traceable to National and International Standards with particular attention being paid in the design to ensuring long term stability. Each microphone is delivered with an individual certificate of calibration giving all the key information relating to its performance. This includes the nominal sensitivity and frequency response along with the environmental data that relates to the calibration.
Norsonic Calibration Laboratory is an international accreditated laboratory. This ensures that the quality of the measured values are at the highest possible level.
Free Field Microphones
All Norsonic microphones are Free Field types. A free field microphone is designed to measure the sound pressure in the sound field, compensating for the influence of the presence of the microphone in the sound field. In effect, the microphone measures the sound pressure as it existed before the microphone was introduced in the sound field, i.e. free field conditions. Applicable standard is IEC 61672 and the former IEC 60651. The free field microphone should be pointed towards the sound source at a 0° angle of incidence.