Mantracourt Wireless System Aids Structural Monitoring

Introduction

Mantracourt Electronics is a leader in high precision measurement electronics and supplies OEM sensor manufacturers and system integrators around the world with innovative and reliable measurement solutions.

This particular project in Italy is typical of how system designers at Mantracourt, in partnership with their customers, provide wireless solutions to aid in the collection of data from structural monitoring projects.

Structural Monitoring        

Misure Meccaniche is an Italian company working in the industrial sector specialising in the field of mechanical measurement, specifically for R&D, seismic and civil engineering. The company’s engineers have a wide range of skills and expertise and work closely with their customers to ensure that the products supplied directly match the application.

Misure Meccaniche has particular expertise in structural monitoring and is always looking at ways to improve the service offered to its clients. Monitoring buildings is carried out to ensure the integrity of the structures and to highlight any defects that may need repair or may prove to be a safety hazard.  

A common application is wall monitoring. For this, inclinometers and displacement sensors are attached to a wall and are typically left in the buildings under test for a period of 3 months. The inclinometers are used to measure tilt and rotation, while the displacement sensors determine crack amplitude. Measurements need to be regularly taken in order to build up a picture over time. The results are then used by the building engineers to decide on what remedial action to take.

Now, thanks to the T24 telemetry monitoring system from Mantracourt, this operation is much more efficient and saves the building engineers time and money as the measurements can be made and sent remotely to a processor, without the need for an engineer to go in and collect the results on a regular basis.

Massimo Nannizzi from Misure Meccaniche worked with Mantracourt system designers to develop a complete wireless monitoring system for structures. Misure Meccahiche offers a service whereby they can carry out the survey themselves and present the results or can just offer the T24 wireless system only.

The T24 system comprises a versatile set of products, based around proprietary acquisition devices that can be mixed and matched to provide high quality remote readings for critical applications. Ideal for this structural monitoring application, the T24 wireless system is specifically designed for multiple data capture and transmission in real time.  The low power, battery equipped, radio units allow data collection over long periods of time without externally supplied power and so are considerably more cost-effective than hardwired systems.

The transmitter unit comprises an ABS case with internal or external battery pack, on/off switch and connection to the sensors. Digital communication and a 24 bit ADC avoids electromagnetic disturbance and the licence free 2.4 GHz direct sequence spread spectrum (DSSS) radio technology offers high integrity, error-free communications which can co-exist with other wireless technologies such as Wi-Fi, Bluetooth, and Zigbee.  For added security, encryption can be set with alphanumeric parameters.

At the heart of the system is the software. This allows for data acquisition, storage and analysis in real time plus alarm and warning threshold management, with an alert email sent to a user-defined address in the event of a problem. For ease of use and reliability it has been developed to run automatically, without end user support and has a reboot capacity with the last system parameters loaded automatically by the software in the event that main power is interrupted and restored. Remote access is secured by a login and password and emails will be stored and power sent later if power or internet access is disrupted. There is also an option for solar or battery backup.

In this particular application carried out by Misure Meccaniche, the T24 system was used to condition and digitise the output from the displacement and inclination sensors and wirelessly transmit the data to a local PC. Both the inclination of the wall and the amplitude of crack in the wall were monitored every 15 minutes, 24/7 by the system. The structural software was used to record the data which was then sent to the engineer every few days via email. An alarm was also set up to alert in case of any overload on the sensors.

Conclusion

Three months was the optimum time to get enough data to allow the engineers to make an informed decision of what remedial work had to be done to ensure the safety and integrity of the structure.

From the point of view of Misure Meccaniche, Mantracourt’s T24 wireless system was easy to set up and operate, being accurate, versatile, secure and reliable. As the company continues to offer its services to operations throughout Italy, wireless is now becoming a viable alternative to hard wired systems.