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Sound and Vibration Instrument Hire and Calibration

Bruel & Kjaer 4128 Specifications

Bruel & Kjaer 4128 Head and Torso Simulator
B&K 4128-C : Head and Torso Simulator £120 a day*

The Bruel & Kjaer 4128 conforms with IEC 60318


Measuring Ranges - Listener Frequency Response

Conforms to ITU-T Rec. P.58 for measurements on telecommunications devices and to IEC60318-7 and ANSIS3.3-1985 for measurements on air conducting hearing aids

Ear Simulator

IEC60318-4/ITU-T Rec. P.57 Type 3.3-based calibrated ear simulator complying with ITU-T Rec. P.57, IEC60318-4 and ANSIS3.25 standards. Output from the ear simulator is via a 7-core 3m cable (2.3m from the bottom of the torso) terminated with a Lemo (1B) plug. For connection to a preamplifier input socket of Bruel & Kjaer Power Supplies, Analysers, etc.
Typical Sensitivity: 12.6mV/Pa (-38 dB re 1 V/Pa) at 250Hz
3% Distortion Level: 162 dB re 20 µPa at eardrum position

Left Ear to Right Ear Tracking

±1 dB up to 5 kHz, ±3 dB up to 8 kHz (measured using the same ear simulator)

Pinna Simulators

Dimensions similar to those specified in ITU-T Rec. P.58, IEC60318-7 and ANSIS3.36. Minor adjustments in the dimensional details have been made which enable Type 4128-C to conform with the acoustic specifications of these documents in the frequency range 100 Hz to 8 kHz. Types 4158-C and 4159-C are supplied with calibrated pinna simulators. An additional pair of uncalibrated hard pinna simulators are available as accessories

Mouth Simulator

Input to mouth simulator via 0.75m cables (0.2m from the bottom of the torso) terminated with banana-sockets
Sound Pressure Distribution: conforms to ITU-T Rec. P.58
Mouth Opening: W×H: 30 x 11mm (1.18 x 0.43")
Equivalent Lip Plane Position, CL: 6mm in front of the sound radiation opening
Mouth Reference Point, MRP: 25mm in front of mouth CL

Continuous Output Level at MRP

Min. 110 dB SPL, 200 Hz to 2 kHz
Min. 100 dB SPL, 100 Hz to 8 kHz
Typical Sensitivity at 1 kHz: 80 dB SPL 2V/500mm
Distortion (Harmonic Components up to 8 kHz) at 94 dB SPL: <2%, 200 Hz to 250 Hz; <1%>250Hz
Max. Average Input Power: 10 W max. continuous average power (at 20°C (68°F))
Max. Pulsed Input Power: 50 W for 2 seconds
Loudspeaker Impedance: 4 Ω

Dimensions and Weight

The main dimensions comply with the dimensional requirements of ITU-T Rec. P.58 and the reports from IEC60318-7 and ANSIS3.36-1985
Total Height, Head and Torso: 695mm (27.4")
Torso Height: 460mm (18"), Width: 410mm (16"), Depth: 183mm (7.2")
External Neck Diameter: 112mm (4.4")
Head Angles: Vertical or 17°
Weight: 9 kg (19.8 lb.
E&OE - specifications subject to change without notice.
* Our standard hire charges are based on a 4-day minimum period, details other options.

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