Nor12090 pages
Product Data
1/2” Microphone Preamplifier
Nor1209
Applications
• Sound level meters
• General purpose
• Laboratory and eld measurements
Features
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Low noise
High input impedance
Wide dynamic range
Wide frequency range
Low output impedance
System Check facility
Large supply voltage range
Detachable preamplier cable
The microphone preamplifier Nor1209 has been designed for general use with most ½” condenser microphone of type
WS2 or LS2 according to IEC 61094-4: Measurement microphones - Part 4: Specifications for working standard microphones.
The microphones may be pre-polarized or use externally supplied polarization voltage up to 200 V. By the use of adaptors,
the preamplifier may be used for other microphone sizes. The frequency response covers the range from below 1 Hz to
above 200 kHz.
The Nor1209 preamplifier may be mounted directly on a sound level meter like Nor140, or may be connected to the instrument by a suitable cable.
The preamplifier is equipped with the system check facility. By supplying a test signal voltage on one of the terminals, the
capacitance of the microphone as well as the complete signal chain from the microphone cartridge to the indication of by
the sound level meter may be checked.
The voltage gain of the preamplifier is very close to one or correspondingly 0 dB. As the input impedance is 10 GΩ, the
attenuation due to loading of the source will mainly be determined by the low input capacitance.
PD 1209 Ed.1 Rev.0 English 02.08
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