Instruction Manual

Sound Level Meter Types 2245 – Instruction Manual Page 38 of 110
The sound level meter can be mounted using Tripod Extension for Hand-held Analyzers
UA-1651. The tripod extension stem is screwed into the Tripod Mounting Thread
situated on the rear end of the sound level meter. The thread on the other end of the
stem is used to mount the assembly to the test rig.
3.6 Periodic Testing of Acoustical Frequency Responses
Acoustical signal test of frequency response can be made with plane progressive waves
in an anechoic facility. However, this is normally very time-consuming and difficult to
do with sufficient accuracy. For the purpose of periodic testing, it is recommended that
you use one of the following Brüel & Kjær products for acoustic frequency response
tests:
 Multifunction Acoustic Calibrator Type 4226
 Electroacoustic Calibrator UA-0033
If the Multifunction Acoustic Calibrator is used, the calibrator must be set to its
Calibration and Pressure sound field modes. The calibrator must be calibrated. Further
details can be found in the Instruction Manual for the Multifunction Acoustic Calibrator.
Acoustical signal test with Electrostatic Actuator UA-0033 should be made only by
personnel that are educated in and familiar with the use of the actuator. The actuator
should be operated with a DC voltage of approximately 800 V and an RMS AC voltage
of approximately 100 V.
Correction data, which must be applied to the sound levels displayed in response to
the sound pressure produced by Multifunction Acoustic Calibrator Type 4226, or in
response to simulation of sound pressure by Electrostatic Actuator UA-0033, in order
to obtain the equivalent sound levels that would be displayed in response to plane
progressive sinusoidal sound waves incident from the reference direction, are given in
Table A. 24 and Table A. 25.
3.7 Mounting for Mechanical Vibrations Tests
The sound level meter is mounted on the shaker using the tripod mounting thread on
the rear end of the sound level meter.
3.8 Testing 1/1-octave-band and 1/3-octave-band Filters
All tests according to IEC 61260 must be conducted with the following settings:
 Use the Electrical Substitute for Microphones calibrated according to section 3.3.2.
 Use the settings for electrical tests according to section 3.2.2.
 Set Measurement settings > Spectrum parameters > Weighting to Z
3.9 EMC Test Procedures
3.9.1 Signal Sources for Immunity Test
Acoustical Source for Testing According to IEC 61672
The acoustic signal, which is used during the immunity test according to IEC 61672, is
applied to the microphone through a ½" plastic hose (a normal water hose) – from a
source outside the test area, see Fig. 3.1. In this way, the acoustic source is not affected
by the RF or magnetic field. The source may be a normal entertainment earphone.