Draw-wire sensors used for wind turbine rotor blade testing

Draw-wire displacement sensors from Micro-Epsilon are playing a vital role in the testing of the latest generation of wind turbine blades at the Fraunhofer Institute in Bremerhaven, Germany.

The test rig at the Fraunhofer Institute simulates the distortion of rotor blades due to the effects of wind forces. The tip of the rotor blade can be distorted by up to 10m due to mechanical loads. The rig is designed to measure rotor blades up to a length of 70m.

During tests, the rotor blade itself is mounted horizontally in the test rig. Steel cables are attached to the rotor using guide pulleys and fixed to the rotor blade at various positions along its length, either directly or via mechanical clamps. Twelve draw-wire sensors from Micro-Epsilon are used to measure the distortion. (Refer to picture on the right).

Two draw-wire sensors for each cable are mounted to the rails on the floor. These sensors measure the movement and the distortion of the rotor blade. The P115 sensors are from Micro-Epsilon's wireSENSOR range and have measuring ranges of between 3m and 10m. The sensors operate with a digital output signal and are particularly robust due to their aluminium housing.

The principle of a draw-wire displacement sensor is relatively straightforward, hence its inherent reliability. A draw-wire sensor works rather like a tape measure, except the user does not have to read off the measurement of the extended tape. The rotation of the drum on which the steel wire is wound is measured automatically. The drum itself incorporates a long-life spring drive, which ensures the steel wire is rewound.

Chris Jones, Managing Director at Micro-Epsilon (UK) Ltd comments: "In addition to wind turbine testing, our draw-wire sensors are being used in a wide range of applications, from general industrial machinery and scissor lifts, through to more specific uses such as dentist chairs, patient lifting tables, theatre stages, pneumatic and hydraulic systems, aircraft landing gear and forklift trucks. Our wireSENSOR range is proving very popular with UK machine builders and OEMs, who require low cost, robust, reliable sensing solutions that can be easily integrated into their customer's existing machine, components or control and automation systems."

The wireSENSOR range uses three main measurement methods: a multi-turn potentiometer, an incremental encoder or an absolute encoder. One of these devices is mounted onto the drum axle, converting the rotary motion of the drum into a signal that can be evaluated. The measured displacement can be output as an analogue current, voltage or potentiometric signal. For a digital output, there is a choice of HTL or TTL, with interfaces for most of the common fieldbus systems, including CANopen, SSI and Profibus.

As with traditional tape measures, the wireSENSOR series is capable of measuring around corners and edges. Micro-Epsilon supplies as accessories deflection pulleys, which deflect the steel wire in the desired direction.

For further information, email: info@micro-epsilon.co.uk or view website: www.micro-epsilon.co.uk    Refer to page 76

ADLINK Technology reveals aTCA Blade with
dual 6-core Intel® Xeon® processor L5638

The aTCA-6150 incorporates 6-core / 12-thread computing power with integrated memory controllers while reducing power consumption

Düsseldorf, March 2010 - ADLINK Technology, Inc. (TAIEX: 6166), a leading provider of trusted telecom computing products, today announced availability of the aTCA-6150, an AdvancedTCA® (ATCA) processor blade featuring dual next-generation 32 nm six-core Intel® Xeon® processor L5638 with 2.00 GHz core-speed, the Intel® 5520 chipset, up to 48GB of DDR3 memory, and an optional PICMG® Mid-size AMC bay for increased computing performance and flexibility.

ADLINK announced the availability of an early-to-market ATCA Blade with dual Intel® Xeon® processor L5518 and AMC bay, the aTCA-6100, in 2009. Following this leading technological achievement, ADLINK debuts the aTCA-6150 as a six-core performance and power consumption enhancement to its ATCA product line. The Intel® Xeon® processor L5638 on 32 nm process technology with 6-core / 12-thread capability gives the aTCA-6150 increased processing performance with more efficient power consumption. This latest ATCA offering from ADLINK is ideal for applications requiring high performance and high-speed data transfer which were formerly thermally constrained.

On-card connectivity includes dual GbE or 10GbE Fabric Interfaces, dual GbE Base Interfaces, dual front panel GbE interfaces, and quad SAS channels which provide leading edge network performance and storage capabilities.

High speed data-transfer on the PICMG 3.1 fabric interface is provided by an Intel® 82599EB 10 Gigabit Ethernet controller with PCI-Express® v2.0, and base interface connectivity is delivered through the Intel® 82576EB Gigabit Ethernet controller, also supporting PCI-Express 2.0. The aTCA-6150 is ideal for carrier-grade applications such as media servers in IPTV, IP multimedia subsystem (IMS) broadband networks, and wireless infrastructures, providing telecom equipment manufacturers (TEMs) and network equipment providers (NEPs) with a powerful, cost-effective solution for mission critical applications and a smooth path for scalability and expansion.

The aTCA-6150 implements two Intel® Xeon® processor L5638 (6-core) or two Intel® Xeon® processor L5618 (4-core) with integrated memory controllers supporting six sockets for DDR3-1066 VLP RDIMM memory up to a maximum of 48GB. Also supporting Intel® Hyper-Threading Technology and Intel® Turbo Boost Technology, the Intel® Xeon® processor 5600 series increases the performance of both multi-threaded and single-threaded workloads, as well as improving energy efficiency. The Intel® Xeon® processor 5600 series features Intel® Trusted Execution Technology (TXT) for safer computing and hardware/firmware security with a higher level of trust and control over computer systems. Also featured are the Intel® AES New Instructions (Intel® AES-NI) that accelerate data encryption and decryption. These advanced practical security features are especially suited to datacom and telecom applications.

ADLINK's new aTCA-6150 offers versatile storage support with 4-channel SAS RAID 0/1, 4GB onboard NAND flash, onboard 2.5" SATA HDD, and modular Fabric riser card for additional PICMG Fabric Interface protocols. The optional mid-size AMC bay supports AMC.1 PCI-Express, AMC.2 Gigabit Ethernet andAMC.3 SATA/SAS storage expansion. I/O features of the aTCA-6150 include Base Interface channels, Fabric Interface channels, 4 front/rear egress ports and update channels. Front panel I/O includes two RJ-45 GbE ports, three USB 2.0 ports, RJ-45 to DB-9 standard serial port and DB-15 connector for analog graphics.

Combining high computing performance, high memory capacity and high speed I/O interface integration, the ADLINK's aTCA-6150 is specifically designed for high-end telecom applications. For further information, view website: http://www.adlinktech.com/AdvancedTCA/   Refer to page 117

SDI-12 submersible level transmitter offers high accuracy and stability

A new range of submersible hydrostatic level transmitters has been launched, which can be used in depths of up to 200 metres. The transmitter offers an SDI-12 digital output and an inbuilt high accuracy temperature sensor.

The SDI-12L range of submersible level transmitters from Impress Sensors & Systems Ltd uses either a stainless steel silicon-based pressure sensor or a ceramic pressure sensor in marine-bronze. Both versions use piezoresistive technology, which provides long term stability and repeatability of measurements.

The transmitter is ideal for a wide range of applications, including the monitoring of river and reservoir levels; tanks and vessels in process plants; seawater and estuary levels; borehole water levels; Tsunami and tidal monitoring systems; wave height measurement; environmental monitoring; and V-notch weir flow measurement.

The stainless steel version offers a higher resolution of pressure measurement to around 12-13 Bit and has a much lower signal-to-noise ratio, providing a very smooth and accurate method of level measurement.

The ceramic pressure sensor version is better suited to marine use, where standard devices may suffer from corrosion. These units are ideal for seawater, estuary and saline applications.

The SDI-12L offers measurement ranges from 0.5mWG up to 200mWG. The output units can easily be adjusted to mmWG, cmWG, inHg and all the standard engineering units required via the SDI-12 interface and command structure. Temperature range of the transmitter is from -20 deg C up to +60 deg C. Accuracy of the inbuilt temperature sensor is less than ±0.1% of full-scale output.

Due to its SDI-12 compatibility, the transmitter can be corrected according to the specific density of the media being measured and local gravity can be set within the device, adding further to the accuracy of the unit.

What is SDI-12?
SDI-12 stands for serial data interface at 1200 baud. This standard was developed in order to interface battery-powered data recorders to micro-processor-based sensors designed for environmental data acquisition (EDA).

EDA is accomplished by using a sensor(s) and a data recorder that collects and saves the data. SDI-12 is a standard communications protocol that provides a method of transferring measurements taken by a smart sensor to a data recorder. The sensor typically takes a measurement, makes calculations based on the raw sensor reading, then outputs the measured data in engineering units.

SDI-12 is particularly useful in applications where battery-powered operation with minimal current drain is required, or where the use of one data recorder with multiple sensors on a single cable is necessary. This includes acquiring hydrologic data at remote sites, which use battery-powered data recorders that operate for long, unattended periods of time.

The SDI-12L is ideal for borehole pump applications. Here, submersible pumps are used to pump water from bottom of the hole to the surface. For the pumps to operate efficiently, they must maintain a level of water above them to prevent them running dry, which can destroy a pump in a short period of time.

The SDI-12L can either be submersed with the borehole pump and attached to the bracketry or retrofitted by lowering the device into the borehole to a known height from the cable distance. The sensor will then output a signal to the surface via the cable, which can then be converted to a level reading. Using a digital process display, this signal can then be used to trigger a relay and turn the pump off if the water level is too low or switch the pump on if the level in the borehole has risen too high. For further information, e-mail: info@impress-sensors.co.uk    Refer to page 80