The Brüel & Kjaer Noise Generator type 1405 is designed to supply well defined white noise in the frequency range 20 Hz to 100 kHz. The generator has a built-in -3 dB/octave filter which is used to weight the white noise in order to produce pink noise in the frequency range 20 Hz to 50 kHz. The filter may also be used separately for other weighting purposes such as automatic bandwidth compensation. The generator also contains a compressor amplifier which is useful when performing frequency response measurements in various applications within the fields of sound and vibration. In such cases the noise generator is often combined with a filter in order to obtain a narrow band signal which is then used to control the compressor. Also the compressor amplifier may be used separately. Features White noise in the frequency range 20 Hz to 100 kHz Uniform spectral density 10 exp4 V ²/Hz Pink noise in the frequency range 20 Hz to 50 kHz Built-in -3 dB/octave filter can be used separately Built-in compressor amplifier with meter Six compressor speeds Signal/hum ratio better than 90 dB Manual and remote generator stop Mains or external battery operation.