Bluetooth system slashes sensor cabling

A Welsh company has come up with a Bluetooth-based wireless sensor networking system which allows any machinery or process to be monitored continuously without the cost or inconvenience of cabling. The WiSNet system, developed by Cardiff-based Expert Monitoring, links any number of transmitter modules spread around a site to a receiver linked to a PC running dedicated software.

The system is already being used to monitor lubrication oil levels at theCardiff site of the steel-maker Celsa. It has also been demonstrated in the electrically noisy environment of electricity sub-stations operated by National Grid Transco. NGT is now looking at installing similar systems across its network.

The system`s battery-powered transmitters (shown above) gather data from up to four sensors or instruments and can transmit this over distances of 200m or more to the receiver. The nominal battery life is at least three years. The transmitters, which can also provide 24V supplies if necessary, can be powered from external supplies where these are available.

According to Expert Monitoring`s managing director, Dr Ken Gale, WiSNet operates in a different way to other Bluetooth-based monitoring systems, which are usually simple peer-to-peer cable replacements. WiSNet is programmable and operates as a multi-drop, wireless-centred network, transmitting packets of data in a similar way to Ethernet.

As well as saving on cabling, the plug-and-go system eliminates the need for sensor power supplies, termination enclosures, data acquisition instrumentation, and collection and analysis software.

Gale has invested around £400,000 to develop the technology. His initial target markets include the water industry as well as the electricity sector.