Measurement Microphones | Class 1 and Class 2 Condenser Microphones

PLACID measurement microphones cover the full range of professional acoustic measurement applications — from precision laboratory work and psychoacoustic research to long-term outdoor environmental noise monitoring and industrial compliance testing. All microphones are manufactured to IEC 61094 working standard specifications and are available with ISO/IEC 17025 accredited calibration providing stated expanded measurement uncertainty.

Measurement microphone selection is primarily driven by the acoustic field in which the measurement is made (free-field, pressure-field, or diffuse field), the required frequency range and dynamic range for the application, the calibration class required by the governing standard, and the signal conditioning interface of the connected preamplifier or DAQ system. PLACID offers expert selection guidance to help you match the right microphone to your application without overspending on specifications you do not need.

Capsule Sizes and Types

• 1/2" free-field microphones — the most common type for general acoustic measurement, environmental noise, and NVH applications
• 1/2" pressure-field microphones — for use in couplers, IEC 60711 ear canal simulators, and any uniform pressure field
• 1/4" free-field microphones — extended frequency range to 40 kHz, reduced diaphragm diffraction for high-frequency applications
• 1/4" pressure-field microphones — for high-SPL measurement and applications requiring small capsule geometry
• Random-incidence microphones — optimised for measurement in diffuse sound fields such as reverberation rooms

Performance Classes

Class 1 microphones meet the tighter tolerance requirements of IEC 61094-4, with tighter sensitivity tolerance, lower directional deviation, and more tightly specified frequency response. They are required for precision measurement programmes, ISO/IEC 17025 accredited testing, and applications where the measurement uncertainty budget must be minimised. Class 2 microphones meet less tight tolerances and are appropriate for environmental noise monitoring, site surveys, and applications where measurement uncertainty requirements are less demanding.

Special Variants

• TEDS (Transducer Electronic Data Sheet) — stores calibration data in microphone body for automatic identification in multi-channel systems
• Low-noise variants — self-noise below 10 dB(A) for measurement of quiet environments and low-SPL signals
• High-SPL variants — dynamic range extended to 155 dB SPL or above for industrial and aerospace applications
• Extended frequency range — response to 40 kHz for high-frequency and ultrasonic measurement

All PLACID measurement microphones ship with a QA/AC factory calibration certificate. ISO/IEC 17025 accredited calibration is available at the time of purchase or as a standalone service for instruments already in service. For measurement programmes where traceability must be formally documented — including ISO 9001 quality management systems, accredited test laboratories, and regulatory submissions — the accredited calibration certificate is the appropriate choice.