MOLES 2.0 (miniature outdoor logger for environmental sound) is a development based on the SV 971A Sound Level Meter.


For more information on MOLES 2.0 or to request a quote, contact our team now:


MOLES 2.0 allows medium to long-term unattended sound monitoring in all conditions. Its lightweight and small design means it is perfect for conducting noise analysis in any location.


  • Long battery life – up to 4 weeks with standard battery
  • Licence of 1/1 octaves
  • Licence of 1/3 octaves
  • Licence of audio events recording
  • Licence of reverberation time analysis (for a limited time only!)
  • Tough weatherproof case
  • Hot swappable batteries
  • External battery option
  • Extension cable included
  • Easily portable

MOLES is an outdoor noise monitoring system which is easily portable, yet low cost. The IP65 rated case contains a lead acid battery which runs the system continuously for over 4 weeks (dependent on ambient temperature and analysis selected). The internal battery can be hot-swapped and external batteries may be connected to extend the life still further.

The supplied SA 271 outdoor microphone protection systems incorporates a desiccator, rain protection and bird spikes, along with a large 130mm windshield, for excellent deduction of wind turbulence noise. Auto calibration can also be enabled, allowing instant access to the calibration menu when a sound level calibrator is applied to the microphone. MOLES is very simple to operate and the SV 971A can either be set up from your PC or using the instrument’s keypad.

SV 971A Specifications

StandardsClass 1: IEC 61672-1:2013, Class 1: IEC 61260-1:2014
Weighting FiltersA, B, C, Z, LF
Time ConstantsSlow, Fast, Impulse
RMS DetectorDigital True RMS detector with Peak detection, resolution 0.1 dB
MicrophoneACO SV 7152, 32 mV/Pa, prepolarised 1/2” condenser microphone
PreamplifierSV 18A detachable (60 UNS thread)
Linear Operating Range
Dynamic Range
27 dBA RMS ÷ 140 dBA Peak (in accordance to IEC 61672)
20 dBA RMS ÷ 140 dBA Peak (typical from noise floor to the maximum level)
Linear Operating Range
Dynamic Range
24 dBA RMS ÷ 126 dBA Peak (in accordance to IEC 61672) in a single range
17 dBA RMS ÷ 126 dBA Peak (typical from noise floor to the maximum level)
Internal Noise Level
(acoustical compensated)
20 dBA RMS in the range NORMAL
17 dBA RMS in the range LOW
Dynamic Range120 dB
Frequency Rangel5 Hz ÷ 20 kHz (+/- 3 dB)
Sound Level Meter ResultsElapsed time, Lxy (SPL), Lxeq (LEQ), Lxpeak (PEAK), Lxymax (MAX), Lxymin (MIN),
where x – weighting filter A/ B/ C/ Z; y – time constant Fast/ Slow/ Impulse
Lden, LEPd, Ltm3, Ltm5
Sound Exposure Meter
Lxy (SPL), Lxeq (LEQ), Lxpeak (PEAK), Lxymax (MAX), Lxymin (MIN), DOSE, (optional)
DOSE_8h, PrDOSE, LAV, Lxye (optional)
(SEL), Lxye8 (SEL8), PLxye, (PSEL), E, E_8h, LEPd, PTC (PEAK COUNTER),
Exchange Rate 2, 3, 4, 5, 6
Measurement ProfilesSimultaneous measurement in three profiles with independent set of filters (x) and detectors (y)
StatisticsLn (L1-L99), complete histogram in meter mode
Data LoggerTime-history logging of summary results, spectra with two adjustable logging
steps down to 100 ms and down to 2 ms in the RT 60 mode
1/1 Octave Analysis (option)Real-time analysis meeting Class 1 requirements of IEC 61260, centre frequencies from 16 Hz to 16 kHz
1/3 Octave Analysis (option)Real-time analysis meeting Class 1 requirements of IEC 61260, centre frequencies from 8 Hz to 20 kHz
Audio Recording (option)Audio recording on trigger or continuous mode, 12 / 24 / 48 kHz sampling rate, wav format
Voice CommentsAudio records on demand, created before or after measurement, added to measurement file
MemoryMicroSD card 32 GB (removable & upgradeable up to 128 GB)
DisplayColour 96 x 96 pixels OLED type
Keyboard8 push buttons
Communication InterfacesUSB 2.0, Bluetooth® 4.2
SV 76 – RS 232 cable with external power supply connector (optional)
Power SupplyFour AAA alkaline or rechargeable NiMH batteries (not included)
Operation time 16 h ÷ 24 h (depending on configuration and environmental conditions)
USB interface 100 mA HUB
Environmental ConditionsTemperature from -10 °C to 50 °C (14 °F to 122 °F)
Humidity up to 95 % RH, non-condensed
Dimensions232.5 mm x 56 x 20 mm (including microphone and preamplifier)
WeightApprox. 225 grams with batteries (Approx. 8.20 oz)

*Continuous product development and innovation are the policy of our company. Therefore, we reserve the right to change the specifications without prior notice


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