리퍼비시 계측기
Type 4189 is our best-selling microphone for 15 years because it produces the best results in its class, and will keep doing so for decades to come, with both CCLD and classical preamplifiers. In addition, this provides great results for electroacoustic measurements like loudspeaker and microphone measurements, and has earned our customers’ trust over many years.
The microphone is a general-purpose workhorse microphone designed for high-precision, free-field measurements with high sensitivity over a frequency range of 6.3 Hz to 20 kHz. Being prepolarized, Type 4189 is especially well suited for battery operated equipment and operation in environments with high humidity. The microphone is universally useful in almost every measurement scenario, it is especially well suited for battery operated equipment – which is why it is fitted as standard to some of our world-leading sound level meters.
Use of Free-field Microphones
At higher frequencies, reflections and diffractions causes a pressure increase in front of the diaphragm of a microphone. If not corrected, for this would result in an increased output voltage.
A free-field optimisation means that the frequency response of the microphone has been designed in such a way that the free-field response at 0 degrees incidence is flat. This microphone is optimised for use with the protection grid in place.
Free-field microphones are commonly used for sound measurement in an anechoic chamber or far away from reflecting buildings, etc. Another area for free-field microphones is for general electroacoustic measurements purposes like loudspeaker and microphone measurements.
Type 4189 is suited for use in class 1 Sound Level Meters and for all high-precision acoustic measurements where a robust and stable free-field microphone with an upper frequency of 20 kHz is required.
A press-fitted, stainless-steel diaphragm ensures superior long-term stability and mechanical robustness – Type 4189 will withstand the 1 m drop test of IEC 60068-2-32.
All Brüel & Kjær Measurement Microphones are assembled in a clean room to ensure that the microphones maintain their inherent low noise floor and high stability, even when used in environments with a combination of high humidity and high temperature.
TEDS Microphones Type 4189 is available in TEDS combinations with either classical or DeltaTron type preamplifier.
The TEDS microphone is considered one unit and has been sealed in a clean environment. The TEDS is programmed with the loaded sensitivity of the actual cartridge and the data is therefore readily available.
The default TEDS template is to IEEE P1451.4 but TEDS to IEEE 1451.4 is available on request.
ï Sensitivity: 50 mV/Pa
ï Frequency: 6.3 Hz ñ 20 kHz
ï Dynamic Range: 14.6 ñ 146 dB
ï Temperature: ñ30 to +150°C (ñ22 to +302°F)
ï Polarization: Prepolarized
Type 4189 ½″ Prepolarized Free-field Microphone
Includes the following accessories:
ï BC-0224: Calibration Chartc
ï BC-5002: Microphone Mini-CDc
TEDS COMBINATIONS
4189-A-021 ½″ Free-field Microphone with Preamplifier Type 2671
4189-A-031 ½″ Free-field Microphone with Preamplifier Type 2699
4189-B-001 ½″ Free-field Microphone with Preamplifier Type 2669-B
4189-C-001 ½″ Free-field Microphone with Preamplifier Type 2669-C
4189-L-001 ½″ Free-field Microphone with Preamplifier Type 2669-L
4189-W-003 ½″ Free-field Microphone with Preamplifier Type 2671-W-001
OPTIONAL ACCESSORIES
Type 2669 ½″ Microphone Preamplifier
Type 2671 ½″ DeltaTron Preamplifier
2671-W-001 ½″ DeltaTron Preamplifier
(version with LLF < 1.2 Hz)
Type 2699 ½″ DeltaTron Preamplifier,
A-weighted
Type 4231 Sound Calibrator
Type 4228 Pistonphone
Type 4226 Multifunction Acoustic
Calibrator
DP-0776 Calibration Adaptor for ½″
Microphones
UA-0033 Electrostatic Actuator
UA-1260 ½″ Angle Adaptor (approx. 80°)
UA-0386 Nose Cone for ½″ Microphone
UA-0237 Windscreen for ½″ microphone,
90 mm diameter
UA-0459 Windscreen for ½″ microphone,
65 mm diameter
BA 5105 The Microphone Handbook
CALIBRATION SERVICES
4189-CAI Accredited Initial Calibration
4189-CAF Accredited Calibration
4189-CFF Factory Standard Calibration