BRUEL & KJAER 2203 - Page 6

General Considerations . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . . . . . . . . . 1 6
Specific
Sound Measurement Procedure . . . . . . . . . . . . . . . . . . . 1 7
3.4. Calibration for Vibration Measurements .................... 18
Using Accelerometer Calibrator 4291 ....................... 18
Using built-in Reference Voltage . .. .... .. .. . .. .. .. .. .. ...... .. 1 9
3.5. Vibration Measurements ......................................... 20
General Considerations ............................................ 20
Specific Vibration Measurement Procedure . . . . . . . . . . . . . . . 20
3.6. Calculation of Vibration Amplitude ............................ 21
With 4291 Calibration, Without Integrator ................ 21
With 4291 Calibration, With Integrator .................... 22
With built-in Calibration, Without Integrator .............. 24
With built-in Calibration, With Integrator .................. 24
4. DESCRIPTION ................................................................... 25
4.1. Condenser Microphone ........................................... 25
4.2. Input Stage .................................................... . ...... 26
4.3. Input Attenuator and Input Amplifier ........................ 26
4.4. Reference Oscillator ............................................... 27
4.5. Weighting Networks ............................................... 28
4.6. Output Attenuator and Output Amplifier ................... 28
4. 7. RMS Detector ........................................................ 28
4 .8. Power Supply· .......... . ............................................. 29
5. OPERATIONAL CHARACTERISTICS
AND ACCURACY ............................................................... 30
5.1. Directional Characteristics ....................................... 30
5.2 ·. Reflection ..................................................... . ........ 36
5.3. Effect of Background Noise ...................................... 37
5.4. Distortion ............................................... . .............. 37
5.5. Effect of Temperature ............................................. 39
5.6. Effect of Humidity .................................................. 39
5.7 . Inherent Noise Levels ............................................. 39
5.8. Effect of Sound Field .............................................. 41
5. 9. Effect
of Vibration ... :.. .. . .. . .. .. .. .. .. . .. .. .. .. .. . .. . .. .. .. . .. .. .. 41
5.1
0. Effect of Atmospheric Pressure ................................ 41
5.11. Effect of Electrostatic and
Electromagnetic Fields
.. .. .. .. .. .. . .. .. . .. .. . .. . .. . .. .. .. . .. .. .. .. 41
5.12. Weighting Networks ............................................... 48