For the first time in its 17 year history, conference organiser, AMA Service, has announced a theme for this year's event and has put energy efficiency at the top of the agenda. It has established an Efficiency Forum, with tabletop exhibits as well as a series of lectures, and podium discussions on the opening day.
The information provided by sensors and measuring systems on the energy conversion and the transportation of energy are essential for efficient industrial energy systems. They provide temperature, pressure and flow data or they provide the data for the composition of gases and liquids. They are used in alternative energy sources, in wind turbines and wind power stations to measure and monitor systems and to measure the attrition rates so that operation is both smooth and reliable.
For consumer applications, sensors are also used to guarantee energy efficiency and are often overlooked as power management ICs dominate headlines. However, effective measurement and monitoring of heating, ventilation and air conditioning systems can save both consumers and organisations significant sums in energy bills as well as help them to meet energy-reduction targets. Finally, the organiser points out, thermography devices identify vulnerable areas of energy use or leakage so that developers can introduce accurate and demand-orientated energy and heating systems.
Automotive design is described as one of the primary driving forces of sensor and mobile measuring development, equaled only by mechanical engineering. Sensors are used for safety, for example, proximity sensors, and engine maintenance. Dynamic pressure sensors are used for diesel particle filters while temperature sensors can be found in monitoring systems for catalytic reduction and in exhaust systems. High-temperature versions control combustion processes in diesel particle filters and to protect a vehicle's turbo charger. Other sensors used around a vehicle are to test and monitor brake pad abrasion and the levels of petrol in the fuel tank.
Vehicle sensors
Angular rate sensors, or gyroscopes, can be found in high-reliability applications like naval and military installations a well as for automotive and mechanical engineering use. Engineers are integrating yaw-rate sensors, used to measure the rotation of the vertical axis in a vehicle, into MEMS modules for ease of installation and reliability. Yet, despite the increased use of these and fibre-optic gyroscopes, which are free of moving parts, there are no interfaces to link to a machine-control or automotive-measurement unit. Until, this year's show in Nuremberg, that is, when GeneSys Elektronik showed off its DWS-CAN precision gyroscope (Figure 1). The company explained that the CAN interface allows straightforward integration into automotive and industrial environments. The rotation rate and angle are transmitted simultaneously via the CAN interface. The voltage-supply range is a wide 9 to 36V DC which allows operation under the diverse and harsh conditions not only associated with, but expected of, motor vehicles.
The precision gyroscope can be used in what are considered challenging stabilisation applications and for precise measurement of dynamic angles about a single measurement axis, says the company. Devices of different measuring ranges are available for recording rotary motion with an accuracy of roughly 1°/h. It also points out that the earth's rotation can influence measurement results by values of up to 15°/h depending on the latitude. The gyroscope compensates for the earth's rotation rate and biasing via the CAN bus. Another advantage is that the fibre-optic technology is robust and maintenance-free, as it has no moving parts.
Fibre-optic sensing
Fibre-optic technology is also the basis for the innovation that was demonstrated by POF-AC at Ohm's University Nuermberg. Its challenge was to develop a roll-up touchpad with variable resolution. Fibre-optics and a CMOS light sensing array delivered the solution. The resulting Touchpad is a rubber foam mat with 12x12 sensing points. A pair of polymer optical fibres, measuring 0.25mm in diameter, both ending in a sensing point are also used. One fibre delivers light, the second one captures light scattered in the foam and transports it to a CMOS light sensing array. The more the foam is compressed, the more light reaches the CMOS detector to measure both the force and the location of the compression(Figure 2). The CMOS chip produces a two-dimensional image of the load on the sensor mat. The more sensing points there are, the higher the image resolution. Depending on the point density, a simple switching touchpad can be produced or, a high resolution measuring device can be created, sophisticated enough to determine load distributions or the shape of objects lying on the mat. It can be used in vehicles to sense the size and shape of the passenger for airbag deployment or it can be used as a roll-up, portable touchpad for mobile applications. The design team claims that the flat design is practical and the fibre-optic technology means that there are not EMI problems and no spark hazard.
Energy harvesting
A new approach to energy efficency is energy harvesting. Micropelt, together with ABB R&D Centres, demonstrated an industrial wireless transmitter that is powered by heat. The aim is to replace the battery in systems with what the project team describes as "an unlimited, green, sustainable, maintenance-free power supply". Using sensors in wireless instruments brings cost reduction benefits as it eliminates the cost of replacement high power batteries, and also increase the flexibility of sensors used in designs.
The joint project has developed the WirelessHART temperature transmitter, which has a thermal energy harvesting unit with two Micropelt Thermogenerators MPG-D651. Each of which has a footprint of 6mm². A temperature gradient of 30°C between the sensed medium and ambient air covers the project's power requirements.
French company, SenseOR strongly believes that how we handle available resources today will condition our future. It also believes that we should use them without degrading our environment. Nowhere is this more keenly felt that in the industrial sector where control and monitoring of equipment ensures it operates at maximum efficiency.
The company's SAW sensors are wireless and are powered by radio waves emitted by the reader unit, remotely interrogating the sensors in real-time. The maintenance-free and lightweight sensors can be mounted on rotating and moving machinery that would ordinarily be inaccessible. The fact that they do not have batteries or active electronic components means that they are also suitable for explosive atmospheres or environments where temperatures can reach up to +175°C. The company's R&D department is working on boosting this to operation in environments of +350°C.
The company's first target application is the measurement of temperature on rotating parts and in environments where very strong electromagnetic fields prevent use of other sensor technologies.
One example is measuring the temperature of the crankshaft bearings in ship engines. The measurements can provide very early warning of any problems, allowing the engine to be stopped and repaired or maintained before serious damage is caused.
The SAW sensors can be used for temperature, pressure, and/or strain measurements in transport, environmental condition monitoring and consumer and industrial goods, such as monitoring the temperature when cooking to avoid energy waste.
Alternative Energy
New forms of energy were also addressed at the show with climate and temperature test for solar and photovoltaic units from Weiss Umwelttechnik. In keeping with the energy theme of the show, the German company introduced the WK 3100 climate chamber which is constructed to the high specifications required for solar and photovoltaic modules (Figure 3).
Photovoltaic modules and solar panels are subjected to temperature and humidity tests according to respective standards EN 61215 or EN 61646 in the climate chambers. The laboratory environmental test detects products' suitability and durability at temperature and humidity levels. To ensure swift development times and time-to-market, these tests have to be concluded in the shortest possible time. Therefore time laps are used to accelerate the impact of any environmental stress which may be expected to occur during the application.
Although small in size, the test chamber has an overall test space volume of 3100litres and it can be loaded with solar panels in their original size of 1.8m. The specimens for test are placed in an specially-developed rack inside the chamber. The vertical routing of the air through the homogenously distributed air on the test space floor provides a constancy, local and temporal, for the temperature conditioning of the panels. In addition, the high-capacity humidification system ensures fast adjustment of the relative humidity after the freezing phase, according to the company.
The chamber is designed to exceed the required temperature and humidity ranges for the industry's standard tests. It operates at temperatures ranging from -60 to +180 °C and within the humidity range of 10 to 95% rh.
The company also offers the WK 2500 chamber which is designed for material testing, approval and for quality inspection. The chamber allows other tests to be conducted including the humidity-heat test, humidity-frost cycle test and the temperature alternating test.
Figure 1: The DWS-CAN brings measurement to automotive and industrial settings.
Figure 2: You can roll with it - the Touchpad uses fibre-optic technology.
Figure 3: Solar energy needs testing too, as demonstrated by Weiss Umwelttechnik's climate chamber.
