½" Low-noise Microphone System Type 40HL

The G.R.A.S. ½″ Low-noise Microphone System Type 40HL measures sound pressure levels well below the threshold of human hearing. It is thus generally suitable for sound-power measurements on even very quiet products. Its very wide dynamic range permits measurements down to below 6.5 dBA re. 20 μPa (in 1/3-octave bands) from 20 Hz to 20 kHz.

Type 40 HL comprises:

• a special high-sensitive ½″ free-field measurement microphone
• a dedicated ½″ low-noise preamplifier

Applications:

• Measurements at very low sound pressure levels
• Measurements on hard-disk drives, computer products, anechoic rooms, quiet rooms, etc.
• Sound power measurements at low levels

Special Features:

• Connects to most high-quality LEMO-connected input modules
• Microphone and preamplifer assembled and sealed under clean-room conditions
• Preamplifier with built-in TEDS, i.e., preprogrammed and programmable with calibration data as a complete unit together with the microphone
• Small and rugged design featuring true ½″ dimensions
• Low power consumption (max. 5.5 mA).

 Download PDF Data Sheet: pd_40HL_ver_17_May_2011.pdf

Related Products:

Type 40HF
Type 40HH
Type 40HT

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System 900 mV/Pa

12.5 Hz – 10 kHz ± 1 dB

10 Hz – 16 kHz ± 2 dB

6 Hz – 20 kHz + 2 dB, –3 dB

6.5 dBA to 113 dB re. 20 µPa