B&K 2250 Light, User Manual, Page: 50 / 208

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2250 Light – User Manual
Charge Injection Calibration
You can check the complete measurement chain during long term measurement using Charge
Injection Calibration. See section 5.6.
5.2 Standard Calibration
To perform the acoustic calibration use Sound Calibrator Type 4231. It provides a stable sound
pressure at 1 kHz and has minimal susceptibility to environmental factors. The procedure itself is
relatively simple, and on 2250 Light the procedure is referred to as the Standard Calibration
procedure.
The procedure for performing an acoustic calibration and instructions on how to fit the
calibrator are given below:
1) Stand away from loud sound sources that may interfere with the calibrator’s signal.
2) Switch on 2250 Light by pressing .
3) Tap on the Main Menu icon and select Calibration from the list of options. A screen
similar to that shown in Fig.5.1 will appear.
Fig.5.1
Initial Calibration screen
This screen contains a bar graph showing the actual sound pressure level and three
placeholders for displaying information about the last calibration.
4) Following the first part of the instruction in the status field, fit Sound Calibrator Type 4231
carefully onto the microphone of the Hand-held Analyzer. (To avoid handling vibrations to
disturb the calibration rest the assembly in a roughly horizontal position on a table or other
flat surface.)
Ensure that the calibrator fits snugly on the microphone.
5) Switch on the calibrator. Wait a few seconds the level to stabilise.