B&K 2250 Light Manual do Utilizador descarregar pdf (Página 208)

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Hand-held Analyzer Types 2250 and 2270 – User Manual

2) Select the 2-Ch. Frequency Analyzer, Logging or Enh. Logging project template.

The project template is displayed at the top of the screen, if it does not display the correct

template tap the Project Template Bar at the top of the screen and select the correct

template from the drop-down menu. (See section 3.3.1 for more details on templates.)

3) Tap the Main Menu icon and select Setup.

4) Select Input > Transducer and select appropriate microphone or accelerometer.

5) Select Frequency Settings > Low Frequency Option and select On.

This will enable extra options for the Low Frequency parameter (Frequency Analyzer

module only) and for the frequency weighting parameters (Fig.17.2).

6) Set Low Frequency to Very Low.

Note: Setting the Low Frequency parameter to Very Low for sound measurements requires

use of the low-frequency microphones, possibly together with Low Frequency

Adaptor UC-0211. These combinations ensure that the measurements fulfil the 1/1-octave

and 1/3-octave filter standards; however, please consult section Table C.5 to see how the

combinations influence the dynamic range of your measurement.

7) Set Broadband (excl. Peak), Broadband Peak and Spectrum Weighting parameters,

as required.

8) Tap to exit Setup.

17.5.1 Controlling the Measurement

The measurement is controlled in the same way you would control a normal Sound Level

Meter measurement, using Start/Pause , Continue , Back-erase and Reset

pushbuttons, see Chapter 3 for more details.

Note: The low-frequency settings require much longer settling times of filters and detectors for

correct results. The instrument automatically takes care of this and waits (after you press Start

) for the needed settling time for the individual detectors.

17.5.2 Displaying the Results

The display frequency axis resolution may be adjusted by tapping the axis and selecting

suitable display frequency limits (Fig.17.7).

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B&K 2250 Light Manual do Utilizador Página 208