The Brüel & Kjær 4189 is a widely specified 1/2-inch free-field condenser measurement microphone used in environmental noise monitoring, sound power measurement, and NVH applications. PLACID Class 1 free-field measurement microphones are designed for the same range of applications with equivalent acoustic performance. This page provides a factual technical comparison to support instrument selection decisions.
Both the B&K 4189 and PLACID Class 1 free-field microphones comply with IEC 61094-4 working standard specifications and are designed for use at 0° free-field incidence. Both can be supplied with ISO/IEC 17025 accredited calibration certificates. The meaningful differences between them are in preamplifier compatibility, calibration documentation approach, and total system cost of ownership rather than in fundamental acoustic performance.
The B&K 4189 uses the standard 1/2-inch externally-polarised preamplifier thread and pin configuration, as does the PLACID PM200C capsule. If you are replacing B&K 4189 capsules in existing B&K preamplifier housings, PLACID can supply replacement capsules screened to the required sensitivity tolerance. Contact PLACID to discuss compatibility with your specific preamplifier model.
PLACID is a practical replacement option for B&K 4189 capsules in existing measurement programmes where the preamplifier infrastructure will be retained. If your B&K 4189 capsules are approaching the end of their calibration interval or showing sensitivity drift, replacing the capsule while retaining the existing preamplifier housing may be more cost-effective than replacing the complete instrument. PLACID capsules are individually screened to specific sensitivity tolerances on request, simplifying the transition within an existing calibrated measurement infrastructure and minimising the recertification effort required.