B&K 2250 Light Manual de usuario descargar pdf (Pagina 22)

CHAPTER 3

Conformance Testing

Fig.3.2

Reference

orientation of Type

2250 relative to the

RF-emitter/receiver

3.6.3 Securing of Microphone Cables during EMC Test

The cable arrangement is common for both the Emission and Immunity tests.

During test, any excessive cable is folded back on itself in an even number of figure eights, as

indicated in Fig.3.2. The microphone and preamplifier assembly is arranged approximately 25 cm

above Hand-held Analyzer Type 2250, with the Microphone facing the RF source.

3.6.4 Accessories

Detailed part descriptions including power supplies, cable types, cable lengths and microphone accesso-

ries are given in Chapter 1 of this manual (see Fig.1.1, Table 1.1 and Table 1.2).

Windscreens have no influence on Emission and Immunity, but the metal parts of UA 1404 change the

resonance frequencies of the microphone and preamplifier assembly. Therefore, measurements must be

taken with UA 1404 mounted, but without the windscreen and raincover mounted.

3.6.5 Testing EMC According to IEC 60804

The exponential time-averaged detectors in Hand-held Analyzer Type 2250 are digital, and their results

are calculated based on the same samples that are used for calculating the linear time-averaged detectors.

Therefore, the L

measurement values will be equal to short L

xeq

values when measuring steady signal

levels.

For this reason, measurement of L

must be utilised during test for Immunity to RF signals when

testing according to both IEC 60651 and IEC 60804. That is to say, only one test has to be carried out

and no special operating mode giving a short duration L

xeq

measurement is provided.

3.6.6 Normal Mode of Operation during EMC Test

The hardware configurations for the normal mode of operation are defined in section 1.3.

Emission

The greatest level of radio frequency emission is radiated from Hand-held Analyzer Type 2250 when

set up as follows:

1) Connect Microphone Type 4189 and Microphone Preamplifier ZC 0032 to the top socket of Type

2250.

2) Select the Sound Level Meter Project Template.

3) On the Setup display:

•Set Measurement Mode to Manual

•Set Input to Top Socket

•Set Micr. Used to the mounted microphone

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