B&K 2250 Light Uživatelský manuál stáhnout pdf (Strana 26)

CHAPTER 4

Specifications

Fig.4.1 Electrical frequency response of Hand-held Analyzer Type 2250 with the Microphone Type parameter set

to ‘Unknown’ (in the Transducers display) for the transducer used, see also Table A.1

Fig.4.2 Deviations from the ideal electrical frequency response with the Microphone Type parameter set to

‘Unknown’ (in the Transducers display) for the transducer used, see Table A.1. Reduced IEC 61672–1

limits are also drawn on the graph

4.6.2 Acoustic Frequency Responses

As can be seen from Fig.4.2, the deviations from the ideal frequency weightings for the A- and C-

weightings differ only slightly at very high frequencies from the deviations for the Z-weighting.

The Z-weighting is included in the data given in section 4.6.4, section 4.6.5 and Appendix A.

Thus the A- and C-weighted free-field and diffuse-field frequency responses can be found by adding

the ideal A- and C-weighted responses to the responses given in section 4.6.4, section 4.6.5 and

Appendix A.

10 Hz

-60 dB

-40 dB

-30 dB

-20 dB

-10 dB

0 dB

10 dB

10 kHz

1 kHz

100 Hz

Frequency weightings

-50 dB

020157

10 Hz

-3 dB

-2 dB

-1 dB

0 dB

1 dB

2 dB

3 dB

10 kHz

1 kHz

100 Hz

Uncompensated

A,C

020158

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B&K 2250 Light Uživatelský manuál Strana 26