We design our noise and vibration monitoring instruments on a single ecosystem to facilitate greater inter-connectivity between devices, components and data solution software. With the same integrated keyboard and intuitive web interface, each instrument uses identical data processing software. This improves productivity and makes it simple to operate — with adaptable features and accessories shared across Orion, Fusion, Duo and Cube. This complementary and harmonised system is part of our commitment to ‘do more with less.’
DUO has obtained the following CEI-61672 Class-1 certification.
These certifications were obtained for both reference directions 0° and 90°.
Calibration and Verification
To simplify the installation of DUO on the site, a function for the automatic detection of a calibration acoustic source allows the performance of a calibration and adjustments without the user needing to do anything more than switch the device on. Furthermore, to ensure proper operation, an integrated measurement-chain verification system performs periodic checks. Electrical verification allows the testing of the entire measurement chain, including the microphone. It consists of injecting an alternating sinusoidal load on the microphone’s terminals at the selected frequencies at one or two levels. The principle is to read reference values and check the deviation with respect to other measured values over time.
DUO natively integrates several modules for communications with external terminals:
- Direct USB connection
- Ethernet network (RJ45 cable)
- Point-to-pointWi-Fi network
- 3G communication thanks to the Modem option (SIM card and subscription not included).
With a communication device (smartphone, tablet, PC…), the user can take control of the DUO using a simple Internet browser. DUO incorporates a web server called dBDUO, which provides access to all device functions (configurations, coding, acoustic calibration and electrical verification, real-time display of instantaneous values…). Connection can be made wirelessly either in Wi-Fi mode or using the 3G modem.
DUO incorporates two very advanced event detection modules.
- Basic module: the user can define an event, comprising a trigger that can be programmed over a maximum of 24 time periods. All settings (overall level, spectral level, rolling Leq, weather settings, etc.) instantaneously stored in the logging interval can be used to define the trigger. The event can be activated according to the days of the week and will trigger different actions: sending of a customized text message, recording of the audio signal, triggering of a parallel recording with a fine logging interval, TTL output, etc.
- Expert module: with this option, up to five events can be programmed, each comprising a combination of logic statements (“AND” or “OR”) for several triggers (max. five).
Deploying cables reduces operational efficiency, so DUO eliminates the need! For the first time, wireless three-axis vibration measurement is available on a sound level meter. The three vibrational signals are recorded at the same time as the metrological audio recording and acoustic indicators (instantaneous and spectral). All these measurements can be processed directly using 01dB software programs such as dBTRAIT and dBFA.
The new “Building acoustics” module of DUO has been developed to improve acousticians’ productivity when doing measurements to assess the acoustic performance of buildings. It includes many innovative features:
- Smart organization of measurements for effective post-processing
- Automatic detection of the type of measurement performed
- Measurement quality indicators for reverberation time (ISO 3382 standard)
DUO includes all the indicators expected by acoustic engineers: Leq, Lp, 1/1 or 1/3 octave spectrum, Fast Slow… These indicators may be measured and stored on the basis of an integration period (IP) of 20 ms (min.) to 3600 s (max.) in 5 ms steps.
In addition, 01dB also offers:
- Perceived aircraft noise level: PNL and PNLT
- Equivalent sliding noise level
- Sliding statistical level
- Noise exposure level.
The latter 3 indicators are mainly used for the monitoring of construction sites for the detection of noisy phases.
DUO offers the possibility of interfacing with the VAISALA WXT536 (6 sensors) and WXT532 (2 sensors) stations. 01dB has selected these 2 stations for their specificity of not having any moving parts. This avoids any risk of mechanical operating failures due for example to ice or wear. The meteorological station and DUO share a common power supply, and the station’s connection cable is 10 m in length, thus allowing great installation flexibility. The meteorological data are stored on the DUO and transmitted in the same way as the acoustic data (USB cable, 3G modem…). The integration period for the meteorological data is a multiple of that applied to the acoustic data. With the remote interface, the user may visualise the meteorological data and wind direction in real time
DMK01 External Unit
The installation of a DUO sometimes requires the use of an external microphone line. To respond to this need, 01dB offers the new DMK01 unit, that comprises:
- stainless-steel body
- specific preamplifier allowing the re-use of the microphone and spike supplied with DUO
- specific anti-wind ball
- a dummy microphone to protect DUO when the microphone is removed.
The unit connects to DUO’s preamplifier input via a cable of 3 to 50 metres in length. The periodic electrical verification function remains available.