Global building efficiency company Johnson Controls is spearheading the use of wireless sensors to ensure that sensors are easier and faster to install and more reliable.
The company offers temperature, carbon dioxide and humidity sensors and aims to launch pressure sensors next. The sensors are powered with high-energy alkaline batteries and, because the sensors have a low-power level, the batteries can reportedly last up to five years. The sensors also alert operators a few weeks in advance when the batteries are running low, and the alarm will regenerate itself when the batteries are replaced, says Johnson Controls GM Neil Cameron.
The company has found that sensors are generally problematic and are the items most likely to fail because they are used in the field and are connected to the system by cables. Problems usually arise from the cable because it is subject to the elements, to damage and to human interference, says Cameron. Wireless technology, on the other hand, enables the use of sensors without cables.
Cameron says that this is a new techno- logy, which is reportedly not yet widely accepted in South Africa, although it is catching on fast in the US. “In a similar way that the Internet took a long time to get off the ground and become a standard, we are now at the stage where wireless is starting to become a standard technology that is accepted and reliable,” he says.
This technology uses a ZigBee platform, which is a global wireless language that connects different devices to work together. He explains that, often, plants or facilities have a number of sensors scattered quite far from the main system or controller. However, wireless technology does not allow the sensors to be too far from one another, typically about 20 m to 30 m, unless higher-powered batteries are used in the sensors, which, he says, is not always practical.
What sets these sensors apart from others is that they use mesh-type technology. He explains that each sensor relays messages to the corresponding sensor closest to the main system, until the message reaches the controller. In this way, the system enables greater distances to be covered using sensors. “Zigbee is an intelligent protocol, so, if one of the sensors was taken away, it would reroute itself, similar to the way the Worldwide Web works, and would connect up again to the control room. The system is also fairly low cost.”
It has been reported that, owing to ongoing improvements in battery design and low-power ZigBee protocols, modern wireless sensors can easily achieve more than 20 years of service life, depending on the battery quality, yearly watts per hour requirements and environmental factors that affect self-discharge.
Meanwhile, Cameron says that there is an extreme skills shortage in the industry, as many skilled [engineers] have emigrated and local skills are not being adequately developed. This means that, when dependent on skills, there are high costs associated with starting local projects as skilled foreign workers have to be brought in. The best solution would be to train local workers and provide them with skills, he says.
To tackle this challenge, the company is investing in tertiary students. It sponsors selected third-year university students and provides them with vacation work at its offices. There are, currently, about 15 students engaged and, once these students qua- lify, they will be fast-tracked through the different sectors of the business, including finance, project management and technical aspects, to upskill them as quickly as possible.
However, the challenge for the company is that these graduates often leave once they have gained enough skills. Despite this, the company accepts this cost as necessary and its role in developing skills as important for the economy and the nation, he says. It hopes that its competitors will start similar skills programmes to augment the supply of skilled employees.
Meanwhile, Cameron believes that the local instrumentation industry is only experiencing the recession now. In the run-up to the FIFA World Cup, Johnson Controls has found that companies have been holding back on new projects and on new product spend. Although it has found that the service business is faring well, there is a lack of investment in capital equipment and this industry seems to be slow. The company hopes that new project and product spend will increase after the FIFA World Cup.
Other African countries are seemingly unaffected by the instrumentation recession, which he attributes to the large projects currently in operation in many of these countries and to foreign investment.
However, the company has noticed a significant increase in exports to the African market. The main areas of growth for its export market are Nigeria, Kenya, Ghana, Botswana and Angola – [in decreasing order of growth]. He believes that the African coun- tries that the company exports to try to order many products from South Africa, because the service and turnaround time are better.