B&K 2250 Light, Руководство пользователя

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108
2250 Light – User Manual
2) Depending on your memory device:
• Insert an SD memory card in a SD card slot at the bottom of the analyzer
• If you have hardware versions 1 – 3, you can insert a CF memory card in the CF card
slot at the bottom of the analyzer
• With hardware version 4, you can insert a USB Type A stick at the bottom of the
analyzer
Note: You cannot record the signal on the internal disk.
3) Tap the Main Menu icon and select Explorer from the list of options. Navigate to
the memory card, create a job folder for the measurements and set the default
measurement job/path as described in Chapter 6.
4) Tap the Main Menu icon and select Setup from the list of options. Set all the
parameters as required for the Sound Level Meter or Frequency Analyzer measurement,
see Chapter 3 and Chapter 10, respectively.
5) Under Signal Recording you can specify the Recording Control parameters as follows:
• Automatic , if you want to start the recording when you start the measurement and stop
when you pause the measurement, and to limit the recording to Maximum Duration , if
Duration Limit is set to On
• Manual Event , if you want to start and stop the recording using the Manual Event
pushbutton during the measurement and to limit the duration of the recording, if
Duration Limit is set to On . In this case the recording will be at least Minimum Dura-
tion long, but no longer than the Maximum Duration . Use Pre-recording Time and
Post-recording Time to specify how much extra you want to be recorded before and
after the event
• External Event , if you want to start and stop the recording using an external trigger
signal, connected to the Trigger Input. See details in Appendix A
• Off , if you do not want to record the signal
6) Set Recording Quality to High , Medium , Fair or Low in accordance with your needs.
Note, however, that high quality requires more disk space than low quality – details in
Appendix A.
7) Set Recorded Signal to either Input A/B-weighted , Input C-weighted or Input Z-weighted
(A/B-weighting is determined by setting the parameter in Setup , Frequency Weightings ,
Broadband (excl. Peak) ). Input C-weighted is suitable for recordings used afterwards to
identify the sound source – it contains all the audible content of the signal, but reduces
the low-frequency noise from wind, etc.
8) Set Automatic Gain Control to On if you just want to listen to the signal afterwards. The
full 120 dB dynamic range (from max.input level and down) will be converted to 40 dB
and the signal is stored as a 16-bit wav-file.
Set Automatic Gain Control to Off if you need to record calibrated signals or need to
analyze the wav-file afterwards on a PC. Select Resolution = 24 bit (recommended) to
cover the full 120 dB dynamic range (from max. input level and down) or select
Resolution = 16 bit and specify the Peak Recording Level .