Bruel & Kjaer 4226 specifications, B&K 4226

Complies with IEC 942 Sound Calibrators, Class 1 at Reference Sound Pressure Level

Reference Sound Pressure Level : at Reference Ambient Conditions
94 dB ± 0.2 dB re 20 µPa, at 1 kHz

Nominal Sound Pressure Levels :
94 dB, 104 dB and 114 dB

10 dB and 20 dB Level Step Accuracy :
± 0.1 dB for f < 8 kHz; ± 0.2 dB for f > 8 kHz

Nominal Frequencies :
from 31.5 Hz to 16 kHz in octave steps, plus 12.5 kHz

Frequency Accuracy :
± 1 % re the ISO 266 stated exact frequencies

Frequency Stability :
better than ± 30 ppm

Reference Ambient Conditions :
Ambient Temperature : 20 °C
Ambient Pressure : 1013 hPa

Influence of Ambient Conditions : at Reference Sound Pressure Level
Ambient Temperature : +0.002 dB/°C in the range -10 °C to +50 °C, max. temp. uncertainty ± 5 °C
Ambient Pressure : +0.00055 dB/hPa in the range 650 hPa to 1080 hPa, max. pressure uncertainty ± 30 hPa to satisfy class 1 requirements
Magnetic Field Sensitivity : no observable effect < 0.01 dB at 100 A/m

Frequency Response :
Pressure Field : Linear 94 dB, 104 dB and 114 dB SPL and inverse A-weighting, 94 dB SPL at 1 kHz
Equivalent 0 ° Free and Random Field : Linear 94 dB SPL and inverse A-weighting, 94 dB SPL at 1 kHz

Level Accuracy at Fixed Frequencies : Lin and inverse A-weighting
Pressure Field Response : re 1 kHz

Total Harmonic Distortion : < 1 %

Additional Functions :
Time Weighting Tests :
Frequency : 2 kHz pre-selected
Test Level : Typically 94 dB, adjustable ± 12 dB approximately
Signal : Continuous reference and tone burst
Level between Bursts : Ref. level -20 dB
Burst Duration : 500 ms Slow and 200 ms Fast

Crest Factor Test :
Frequency : 2 kHz pre-selected
Test Level : typically 94 dB, adjustable ± 12 dB approximately
Signal : continuous reference and tone burst of 40 Hz repetition frequency. Crest Factor 3 at pre-selected and higher frequencies
Note : All burst signals consist of an integral number of sine waves with amplitude shifting at zero crossing

Dose Meter Calibration :
Calibration Period : 30 s : Obtained doses at 1 kHz:

AC Output :
Output Voltage : 12.5 mV ± 0.5 mV at settings 94 dB, 1 kHz and pressure mode.
Voltage changes according to the selected level, type of microphone , sound field and function. Signal for testing time weighting and crest factor capabilities as above, except that the crest factor is 10
Note: The acoustic output signal is switched off when a plug is inserted in the AC OUT socket

Output Impedance : 600 Ω short circuit proof
Frequency Response : ± 0.2 dB from 31.5 Hz to 16 kHz in pressure mode
Note : The acoustic output is switched off when a plug is inserted in the AC OUT socket

External Generator Input :
Input Voltage : 0.5 V to 1.5 V
Input Impedance : 47 kΩ

Frequency Response in the Coupler :

Note: These tolerances are relative to the inverse pressure response of the reference microphone. Only Pressure and Linear response are possible with external generator.

Stabilization Time: The LED corresponding to the selected frequency lights continuously when the SPL is stabilized, typically 2 to 10 seconds

Power Supply
Batteries : 4 x LR6 - 1.5 V alkaline
Battery Life : 10 hours approximately at 20 °C with alkaline batteries
Battery Check : The 'Batt Low' LED is lit when reaching the last 10 % of the battery life

Effective Coupler Volume
Approximately 400 cm³ at 31.5 Hz, decreasing to approximately 30 cm³ at 1 kHz, obtained by feedback

Environmental
Ambient Temperature : -10 °C to +50 °C
Ambient Pressure : 650 hPa to 1080 hPa
Ambient Humidity : 5 % to 90 %RH

Dimensions and Weight including mahogany case
Length : 265 mm
Width : 125 mm
Height : 62 mm
Weight : 1.5 kg

31.5 Hz - 125 Hz	± 0.15 dB
250 Hz - 500 Hz	± 0.10 dB
2 kHz - 4 kHz	± 0.15 dB
8 kHz	± 0.25 dB
12.5 kHz - 16 kHz	± 0.50 dB

31.5 Hz - 125 Hz	± 0.20 dB
250 Hz - 500 Hz	± 0.10 dB
2 kHz	± 0.20 dB
4 kHz	± 0.30 dB
8 kHz	± 0.50 dB
12.5 kHz	± 1.00 dB
16 kHz	± 1.50 dB

SPL	IEC	ANSI
94 dB	0.26 % ± 0.01 %	0.18 % ± 0.01 %
104 dB	2.64 % ± 0.02 %	0.73 % ± 0.03 %
114 dB	26.7 % ± 0.02 %	2.90 % ± 0.12 %

31.5 Hz - <8 kHz	± 0.15 dB
8 kHz - <12.5 kHz	± 0.25 dB
12.5 kHz - 16 kHz	± 0.50 dB

Manufacturers' Specifications Bruel & Kjaer 4226

Manufacturers' Specifications

Bruel & Kjaer 4226