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Sound and Vibration Instrument Hire and Calibration

Bruel & Kjaer 4321 Sound Calibrator Specifications


Bruel & Kjaer 4231 Acoustic Calibrator
 
B&K 4231 Sound Level Calibrator - Class 1 £ 3 a day *
 

Standards Satisfied


IEC942 (1988), Sound Calibrators, Class 1
ANSI S1.40-1984 (R 1997), Specifications for Sound Calibrators
 

Specified Microphone Types:


(Conforms to IEC 942 Class 1)
Bruel & Kjaer 1" and 1/2", 1/4", 1/8" with adaptor
 

Nominal Sound Pressure Level:

94.0 dB ± 0.2 dB or 114.0 dB ± 0.2 dB re 20 μPa at reference conditions
 

Equivalent Free-field Level:


(0° incidence, re Nominal Sound Pressure Level)
-0.15 dB for 1/2" Bruel & Kjaer Microphones
 

Equivalent Random Incidence Level:


(re Nominal Sound Pressure Level)
+0.0 dB for 1", 1/2", 1/4" and 1/8" Bruel & Kjaer Microphones
 

Reference Conditions:


Ambient Temperature: 20 °C (68 °F)
Ambient Pressure: 1013 hPa
Ambient Humidity: 65 %RH
Load: Microphone Type 4134 (0.25 cm3)
 

Ambient Conditions:


Temperature: -10 ° to +50 °C (14 ° to 122 °F)
Pressure: 650 to 1080 hPa
Humidity: 10 to 90 %RH (without condensation)
Effective Load Volume: 0 to 1.5 cm3
 

Influence Of Ambient Conditions:

(typical)
Temperature Coefficient: ± 0.0015 dB/°C
Pressure Coefficient: +8.10 -5 dB/hPa
Humidity Coefficient: 0.001 dB/%RH
 

Level Stability:


Short Term: Better than 0.02 dB (as specified in IEC 942)
One Year: Better than 0.05 dB (õ=96%)
Stabilisation Time: 5.0 s
 

Nominal Effective Coupler Volume:

>200 cm3 at reference conditions
 

Frequency:

1 kHz ± 0.1 %
 

Total Harmonic Distortion (THD):

<1 %
 

Storage Temperature Range:

-25°C to 70 °C (-13°F to 158 °F)
 

Protection Class:

(with leather protection case) Ip50 (IEC 529)
 

Batteries:


Type: 2 x 1.5 V IEC Type Lr6 ("AA" size)
Lifetime: Typically 200 hours continuous operation with alkaline batteries at 20 °C (68 °F)
Check: When Type 4231 stops working continuously and only operates when holding in the button, the batteries should be replaced.
 

Dimensions (Without Case):


Height: 40 mm (1.5")
Width: 72 mm (2.8")
Depth: 72 mm (2.8")
 

Weight:

150 g (0.33 lb.) (including batteries)
 
E&OE - specifications subject to change without notice.