Measurement microphones
Measurement microphones are transducers for quantifying sound pressure. They are typically used with sound level meters to provide a way to indicate the prevailing sound level in a hand-held instrument of remotely deployed system. They differ from other types of microphone, such as those found in a cell-phone, or used in a recording studio, but having a quantified sensitivity expressed in output voltage for an applied unit sound pressure as a function of frequency, and may be fully characterised in other respects such as their dependence on the ambient environmental conditions.
What do we cover
WG5 covers the specification and calibration of measurement microphones using both in the laboratory as reference calibration standards and in the field for practical sound measurement. Calibration techniques include primary methods suitable for establishing measurement standards and secondary methods using comparison techniques and electrostatic actuation. Calibration in both a pressure field and a free field are covered.
WG5 does not cover requirements for microphones used in audio engineering or telecommunications applications
Why is it important
Standardisation is necessary for a range of reasons, including:
•Establishing performance requirements to enable high quality devices to be produced and marketed
•Consistency in the application of calibration principles
•Description of best practice and current knowledge for primary calibration to support national measurement institutes in establishing measurement standards for sound in air
Experts / Countries
Active projects
Publications
IEC 61094-1:2000: Measurement microphones – Specifications for laboratory standard microphones https://webstore.iec.ch/searchform&q=61094-1
IEC 61094-2:2009: Measurement microphones – Part 2: Primary method for pressure calibration of
laboratory standard microphones by the reciprocity technique https://webstore.iec.ch/searchform&q=61094-2
IEC 61094-3:2016: Electroacoustics – Measurement microphones – Part 3: Primary method for free-field calibration of laboratory standard microphones by the reciprocity technique https://webstore.iec.ch/searchform&q=61094-3
IEC 61094-4:1995: Measurement microphones – Part 4: Specifications for working standard microphones
IEC 61094-5:2016: Electroacoustics – Measurement microphones – Part 5: Methods for pressure calibration of working standard microphones by comparison
IEC 61094-6:2004: Measurement microphones – Part 6: Electrostatic actuators for determination of frequency response
TS 61094-7:2006: Measurement microphones – Part 7: Values for the difference between free-field and pressure sensitivity levels of laboratory standard microphones
IEC 61094-8:2012: Measurement microphones – Part 8: Methods for determining the free-field sensitivity of working standard microphones by comparison
IEC 61183:1994: Electroacoustics – Random-incidence and diffuse-field calibration of sound level meters
Richard Barham
Convenor