B&K 2250 Light Manual do Utilizador descarregar pdf (Página 26)

Hand-held Analyzer Types 2250 and 2270 – User Manual

2.5 Assembling the Analyzer

2.5.1 Charging the Battery for the First Time

Battery Pack QB-0061 comes charged to approximately half capacity on initial delivery.

Before assembling your analyzer for the first time, it is recommended that you fully charge the

battery pack, by connecting Mains Power Supply ZG-0426 to the external power socket. It

should take approximately 8 – 10 hours.

On hardware versions 1 – 3, the battery charge indicator shows a steady green light when

external power is applied (and the battery is charging), and a flashing green light when

charging has finished.

On G4 hardware, the light is red when the battery is charging and green when charging is

finished.

You can leave the analyzer with external power on, even when the battery is fully charged..

Refer to section 9.4.3 for more information on the analyzer’s battery.

2.5.2 Making Good Measurements

The fact that you are using your Type 2250 or Type 2270, which fully complies with the

IEC 61672–1 standard, ensures you always make good measurements. The analyzer should be

set up using the following recommended assembly instructions. This is to minimise the

influence of acoustical reflections during measurements. All the components described below

are shown in Fig.2.1 and Fig.2.4.

Another set of instructions are provided in section 2.5.3, for situations where you need to

position the microphone at a distance from the analyzer, while still complying with the

standard.

Placing the Measurement Microphone

The measurement microphone must be placed away from shielding, reflecting, or absorbing

objects. In a diffuse sound field, absorbing objects will reduce the measured sound levels. In

a free sound field, reflecting objects can change the measured sound levels. Typically, the

sound level 0.5 m from a plane reflecting wall is 3 dB higher than if there was no wall.

The operator of the system may be personally shielding, absorbing, and reflecting, and can be an

additional noise source. Measure downwind in dry conditions with a windspeed less than 5 m/s.

The optimum position for the microphone is best found by trying different positions and

observing the resulting sound levels.

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B&K 2250 Light Manual do Utilizador Página 26