The Brüel & Kjær 4190 is a 1/2-inch free-field externally-polarised condenser measurement microphone. It is the externally-polarised (200 V DC) counterpart to the pre-polarised B&K 4189 — both are free-field designs for the same range of acoustic measurement applications, but the 4190 requires a preamplifier that supplies 200 V polarisation voltage, while the 4189 is pre-polarised and can be powered by an IEPE current supply. PLACID PM200 series measurement microphones are also externally-polarised (200 V) free-field designs, intended for the same application range as the B&K 4190.
Externally-polarised condenser microphones are the traditional choice for precision laboratory measurement and accredited testing. The 200 V polarisation voltage must be supplied through a compatible preamplifier. This configuration is specified in IEC 61094, and the primary and secondary calibration methods of IEC 61094-2 and IEC 61094-6 are defined for externally-polarised microphones. For applications where IEC 61094 compliance and the lowest achievable measurement uncertainty are required, externally-polarised configurations remain the standard.
Contact PLACID to discuss compatibility if you are evaluating PLACID PM200 capsules as replacements for existing B&K 4190 capsules in your preamplifier housings. Sensitivity screening to a defined tolerance is available for replacement capsule orders of five or more units, simplifying traceability continuity in an existing calibrated measurement chain. The PLACID long-term stability programme provides quarterly sensitivity monitoring data as supplementary evidence for calibration interval justification — documentation not routinely available from other suppliers.