Dewesoft IOLITE® 3xMEMS | Sistem Akuisisi Data

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Tailor-made data acquisition devices for structural health monitoring applications. Ideal price-performance solution for permanent condition monitoring on structures such as bridges, buildings, antennas, and stadiums.

IOLITEicw 3xMEMS-ACC overview

IOLITEicw 3xMEMS-ACC are integrated sensing devices for measuring vibration, inclination, velocity, displacement, pitch, and roll. Acceleration is measured by an integrated triaxial MEMS accelerometer inside the device. The accelerometer is tightly attached to the mechanical chassis.

Analog-to-digital conversion (ADC) is also done inside the device. This eliminates any noise picked up by analog cabling.

A microprocessor inside the device transmits the acceleration samples over into DewesoftX data software running on a Windows PC. Alternatively, the devices can also be connected to any controller running an EtherCAT master. Sensor scaling is automatic, Thedata in g’s or m/s2 is readily availableto the user.

Aninternal temperature sensormounted inside the device measures the temperature of the MEMS accelerometer. These readings are also displayed inside DewesoftX data acquisition software as a system monitor channel. The values are updated once per second.

IOLITEicw 3xMEMS-ACC devices are designed for a tailor-made structural health monitoring solution. They are ideal for permanent condition monitoring on big structures such as bridges, buildings, antennas, stadiums, big machines, etc.

Available device configurations

IOLITEicw MEMS devices are available in several configurations:

• IOLITEicw 3xMEMS-ACC-8g: Triaxial MEMS accelerometer with EtherCAT interface, ±2g to ±8g measurement range, 0 – 1000 Hz bandwidth, 4 kS/s sampling rate, 96 dB dynamic range, and 25 µg/√Hz spectral noise density. Aluminum housing, plastic cable glands, IP67

• IOLITEicw 3xMEMS-ACC-40g: Triaxial MEMS accelerometer with EtherCAT interface, ±10g to ±40g measurement range, 0 – 1000 Hz bandwidth, 4 kS/s sampling rate, 96 dB dynamic range, and 25 µg/√Hz spectral noise density. Aluminum housing, plastic cable glands, IP67

• IOLITEicw 3xMEMS-ACC-S: Low noise triaxial MEMS accelerometer with EtherCAT interface, ±15g measurement range, 0 .. 460 Hz bandwidth, 1 kS/s sampling rate, 137 dB dynamic range, and 0.7 µg/√Hz spectral noise density. Aluminum housing, plastic cable glands, IP67

• IOLITEicw 1xMEMS-ACC-Z-8g: Uniaxial MEMS accelerometer with EtherCAT interface and ±2g, ±4g, and ±8g measurement ranges, 0 – 1000 Hz bandwidth, 4 kS/s sampling rate, 96 dB dynamic range, and 25 µg/√Hz spectral noise density. Aluminum housing, plastic cable glands, IP67

• IOLITEicw 1xMEMS-ACC-Z-40g: Uniaxial MEMS accelerometer with EtherCAT interface and ±10g to ±40g measurement range, 0 – 1000 Hz bandwidth, 4 kS/s sampling rate, 96 dB dynamic range, and 25 µg/√Hz spectral noise density. Aluminum housing, plastic cable glands, IP67

• IOLITEicw 2xMEMS-INC: Static bi-axial inclinometer with Measurement range: +-15 deg, resolution: 0,001 deg, relative accuracy: 0,01 deg. Aluminum housing, plastic cable glands, IP67

Distributed EtherCAT® architecture

EtherCAT® protocol allows the IOLITE devices to be easilydistributed across large structures. Devices can span100m node-to-nodewith only one cable running between them for signal, power, and synchronization.

By using optical converters even distances of more than20 km between the devices can be covered while still keeping a 1us synchronization between the devices.

Static inclinometer to measure pitch and roll angles

We offer two versions of IOLITEicw 3xMEMS devices that can be used as a static two-axial inclinometer. Devices can be used to measure the pitch and roll angles (around its X and Y axes with the Z-axis positioned vertically).

• IOLITEicw-3xMEMS-ACC-8g-INC:The same specs as IOLITEicw-3xMEMS-ACC-8g with an integrated inclinometer.

• IOLITEicw-2xMEMS-INC:A static two-axial inclinometer measurement device. Measurement range: +-15 deg, resolution: 0,001 deg, relative accuracy: 0,01 deg.

They can be used for static inclination monitoring of structures, for example, bridges, viaducts, high-rise buildings, wind turbines, etc. It measures roll and pitch angles (about its X and Y axes) with the Z axis positioned vertically.

A static two-axial inclinometer offers the following specs:

• Measurement range: +-15 deg

• Resolution: 0,001 deg

• Relative accuracy: 0,01 deg

IOLITEicw-3xMEMS-ACC-T to measure acceleration and temperature on structures

The IOLITEicw-3xMEMS-ACC-T version features an additional M8 connector at the front to which a temperature sensor can be connected. This allows a simple and inexpensive addition of a temperature measurement point in monitoring applications on bridges, wind turbines, and other structures.

Only a dedicated temperature sensor is compatible and must be ordered separately. It is a digitized temperature sensor with the following specs:

• Measurement accuracy: +-0.5 °C

• Measurement range:-55 to 125 °C

• Environmental protection: IP66.

1-wire protocol is used for communication between the sensor and the 3xMEMS-ACC device. Maximum cable length is 10 m.

Seismic noise performance

IOLITEicw 3xMEMS devices have a very low spectral noise density. The IOLITEicw 3xMEMS-ACC-S has a0,7 µg/√Hzspectral noise density and residual noise of2µg (RMS)at 100 Hz bandwidth. Its performance can be easily compared to the best-in-class Force Balance accelerometers.

The IOLITEicw 3xMEMS-ACC has25 µg/√Hz spectral noise densityand100 µg residual noiseat 50 Hz bandwidth.The FFT recorder on the right shows the residual noise of the IOLITEicw 3xMEMS-ACC three axes at the sample rate of 100 S/s resulting in a 96 dB dynamic range.

Ready to measure displacement

Even though the IOLITEicw 3xMEMS-ACC devices measure acceleration, can be also used to preciselymeasure displacementby integrating the acceleration twice and applying appropriate filtering. The task is straightforward thanks to the DewesoftX data acquisition software.

In the experiment shown below the linear displacement of the IOLITEicw 3xMEMS-ACC is measured directly with a laser distance sensor and also calculated from measured acceleration. Results show great accuracy even at a low frequency of 1.5 Hz.

Product testing and validation

Hardware repairs or replacements are expensive on structures such as bridges. Therefore IOLITEicw 3xMEMS-ACC was put through in-depth product validation tests that ensure reliable operation within its specifications.

Standard testing procedures include vibration and temperature cycle tests to check the durability and specify drifts in measured acceleration.

Permanent outdoor mounting with the IP67 waterproof casing

IOLITEicw 3xMEMS-ACC devices are available in a waterproof aluminum casing with cable glands. The enclosure is designed to be mounted outdoors and is fully waterproof.It complies with IP67 environmental rating. Devices can operate in a wide temperature span from -40°C to 65°C.

Cables are inserted through the cable glands at the installation location and crimped to the male RJ45 connectors. The female RJ45 connectors of the IOLITEicw 3xMEMS-ACC are located inside the waterproof enclosure. The top lid can be fixed to the enclosure using an O-ring seal and four bolts after the connectors are mated.

The outdoor enclosure automatically vents the air to equalize pressure inside the enclosure to the outside air pressure while it does not allow water to pass into the enclosure. This prolongs the life span of the seal and increases the durability of the enclosure.

Historian database storage

IOLITE data acquisition device can be installed for long-term or permanent monitoring. This kind of measurement requires efficient data storage. For that, we provide Dewesoft Historian service. Historian is a time-series database service based on the MQTT messaging protocol for the Internet of Things (IoT).

Historian is based on an open-source InfluxDB database and is a perfect solution for long-term monitoring. Data in the Historian can be accessed in two ways:

1. Web clients:any modern web browser can be used as a web client to access real-time data stored in the Historian. The solution is based on another open-source project Grafana. It allows to set up of completely customized views and is a perfect solution for real-time dashboards.

2. Desktop client: the desktop client is an instance of our award-winning DewesoftX software. It allows you to import historical data from the Historian database for in-depth analysis.

Historian is available to be installed on your own server or as a completely managed cloud service.

Visit the Dewesoft Historian web page for more information.

Installation accessories

Devices are daisy-chained with a standard ethernet network cable. It is recommended that the cable is shielded (SFTP, CAT5e) and has a minimum of 24 AWG wire thickness. The cable must have 4 wire pairs. The maximum distance node-to-node is 100 m.

A passive PoE (power over ethernet)power injector is necessary for merging the EtherCAT signal and power into a single cable. The IOLITE® power injector is an industrial power injector with embedded burst and surge protection electronics.

Industrial application and system integrations

Systems based on IOLITE® 3xMEMS data acquisition hardware and DewesoftX software are installed all over the globe to perform important structural monitoring. One of our bigger system integrators,ESSEBI, is integrating IOLITE® 3xMEMS accelerometers in permanent structural monitoring systems.

We are delighted with the noise performance of the device. It allows us to perform operational modal analysis. The ease of use of the total solution together with software is very important to us as it is completely plug-and-play.

Learn more

• Structural monitoring with MEMS accelerometers

• Dynamic measurements on suspension bridges

• Structural monitoring of Orvieto cathedral

If you are interested in becoming a system integrator pleasecontact us.

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