New Wireless Miniature Piezoelectric Accelerometer Technology at Sensors & Instrumentation Exhibition
Over the last few years RF wireless connections have come a long way and have replaced physical wiring in many industrial applications. Such applications often require sensors to be installed at remote, difficult to access or hostile locations and clearly, in such cases, cabling can be impractical. Wireless sensors offer many benefits for simplified installation and avoid the need for long cables which can cause signal degradation and noise.
Although wireless sensors would seem to have many benefits there are challenges to be considered due to data bandwidth, power and whilst wireless communication for static and quasi-static sensing is relatively simple, it is far less straight forward for dynamic signal measurement.
There is no ‘ideal’ wireless sensor that could be used for all plausible applications. Development of any wireless sensor requires an in-depth understanding of the environment, usage and expectations from the device.
A majority of existing wireless accelerometers predominantly use MEMS (Microelectromechanical Systems) for sensing. They are often designed with the intention of allowing a number of devices to be networked together, each operating as a node. Each of these nodes consist of processor, memory and radio. The manufacturers have devised a complete sensor network system which includes gateway and a software program with simple user interface.
Wireless MEMS accelerometers suffer from common disadvantages including low measurement range, low sensitivity, susceptibility to noise and limited frequency bandwidth. In addition they tend to be large and heavy making them unsuitable for test and measurement applications.
DJB is focused in the manufacture of test and measurement accelerometers and is already a world leader in miniaturisation and high temperature devices. Over the last 2 years it has dedicated itself to developing Piezoelectric wireless accelerometers. The DJB sensor will be miniature in size (using proven DJB technology), high sensitivity, wide measurement range and enabled with Bluetooth Low Energy for wireless transmission.
The proposed accelerometer, which uses DJB’s unique Konic shear piezoelectric ceramic design, will have a measurement range of up to 5000g with frequency range from 0.5 to 8000Hz. High speed sampling will give the user higher usable bandwidth when compared to MEMS devices.
The wireless sensor will be easy to use for the operator with functions for initiating and terminating the transfer, connectivity check and basic diagnosis on board, in addition to an alarm system for any connection loss.
Power consumption is a critical challenge while using wireless sensors and power management is an important issue to be dealt with. Consumption is at its highest while transmitting data, so management of wireless communication is essential to extend battery life.
The DJB solution is an event-driven product that transfers data only when requested by the user, otherwise it stays in a low power mode. Power consumption is significantly reduced in such systems.
DJB’s journey down the wireless accelerometer road has only just begun but the significant benefits and potential are already very clear. The options for packaging wireless communication alongside DJB’s existing range of microminiature accelerometers offers significant advances for testing in fields such as human vibration, sports science, medicine and many others.
If you have a challenging application that would benefit from wireless accelerometers or have a new requirement looming please get in touch, the more information we have about your requirements the better we are placed to develop the right solutions.