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Low Noise IEPE Microphone Interface

IEPE microphone interface with measuring range from 13 dB(A) to 97 dB(A)

This IEPE measurement microphone USB interface was specially developed for high-quality condenser measurement microphones for measuring particularly low sound levels.

The inherent noise of the PnDL-100 is 13 dB(A) and the inherent noise of WS2F class 1 measurement microphones with 50 mV/Pa sensitivity is 15 dB(a) to 17 dB(A).

The PnDL-100 is ideal for noise measurements from 13 dB(A) to 97 dB(A).

Supported operating systems: Android – Linux – Windows – macOS

PnDL-100

Linux DAQ Linux ADC Windows DAQ Windows ADC
Analog Input
2ch single ended BNC, IEPE
Inherent noise
13 dB(A) with 50 mV/Pa mic sensitivity
IEPE power fixed
21 Volt / 4mA
Fixed input range
0.1 V Volt Peak
Bandwidth
1 Hz to 24 kHz (-3dB)
10 Hz to 22 kHz (-0.5dB)
Sampling Frequency
48 kHz, – 44.1 kHz – 32 kHz – 22.05 kHz
16 kHz – 11.025 kHz
Absolute accuracy
1 % typical
Gain accuracy
0.2 % or better
Distortion
< 0.05%
Dynamic range
> 100 dB(FFT-based)
Pass band ripple
0.05 dB
Powered by USB Port
Power consumption < 1W
Temperature range
+/-0 to +50 °C
Dimensions
57 (w) x 104 (d) x 28 (h) mm
Weight
110 g

Supported operating systems: Android – Linux – Windows – macOS

Plug.n.DAQ Lite Software Compatibility: ARTA – Audacity – DASYLab – imc WAVE – LabVIEW – ME’Scope – NVH-IMP – NVH-FFT – Visual Analyzer – WavePad Sound Editor – Sigview – Soundcard Oscilloscope – SO Analyzer – SpectraPLUS-RT – SpectraPLUS-SC – Multi-Instrument

Low noise IEPE microphone at 10 volt range input, sound pressure level and microphone sensitivity.

A typical 1/2″ measurement microphone delivers a voltage of 50 mV at 1 Pascal. 1 Pascal corresponds to a sound pressure level of 94 dB. 94 dB is already very unpleasant for humans and is only tolerated in rare situations.
 
During a normal conversation, the sound pressure level is below 74 dB, i.e., 20 dB lower. 20 dB quieter is a factor of 10 quieter.
 
This means that at 74 dB, the microphone only delivers 5 mV.
 
Assuming that end-of-line testing involves acoustically testing parts in a soundproof test chamber, it can be assumed that the measurement microphone delivers only a few microvolts.

IEPE DAQ with low inherent noise

The choice of the input measurement range for the measurement data acquisition is therefore crucial. Assuming that the measurement card has a measurement range of 10,000 mV and the measurement microphone is exposed to a sound pressure level of 74 dB, which delivers 5 mV, the 10,000 mV measurement range is significantly too coarse for this application.
 
The difference becomes even more apparent when you consider that verbal interaction is reduced in the office. At a sound pressure level of 54 dB, the voltage detected by the measurement microphone is 0.5 mV.
 
The comparison scenario with a scale with a 10,000 kg measurement range illustrates that weighing a 0.5 kg object is associated with a high degree of inaccuracy.
 
Our solution for this application is the PnDL-100 with an input measurement range of 100 mV, which delivers an acoustic measurement range of 13 to 97 dB(A).