-------------------------Monitor------------------------ The Newsletter for PC-Based Data Acquisition and Control Issue 157 www.windmill.co.uk August 2011 --------------------ISSN 1472-0221---------------------- Welcome to Monitor, the newsletter for data acquisition and control. This month we are slashing the price of strain measurement from £775 to £475, that's 770 USD or 540 Euro. Read below for more information or visit https://www.windmillsoft.com/daqshop/strain-measurement.html We hope you find the newsletter useful, but should you wish to remove yourself from our mailing please go to Monitor Newsletter CONTENTS ======== * Windmill News: Strain Gauge Package Reduced - 5 Tips on Measuring Strain - Digital Inputs, Outputs and Counters - Windows Software - Technical Support * DAQ News Round-up * Data acquisition and control exhibitions ________________________________________________________ ________________________________________________________ Windmill News: Strain Gauge Package Reduced ________________________________________________________ Windmill's 751-SG package has 16 channels with which you can monitor strain gauges, balanced bridges like pressure transducers and voltage signals. This USB unit also provides 32 digital inputs and outputs and 8 counters. Connect eight units to one PC and monitor 128 strain gauges. We have cut the cost of this easy-to-use strain measurement system by £300 at our on-line catalogue: https://www.windmillsoft.com/daqshop/strain-measurement.html Measuring Strain ================ Here are five points to consider when choosing a strain measurement system. 1. The initial unstrained measurement is often much larger than the change in signal due to strain. If this initial value is not accounted for, it restricts the resolution you can obtain - that is the smallest signal you can measure. The 751-SG system zeroes or balances the strain gauge bridge, nulling the offset of the initial voltage. So instead of measuring over a wide range, 0 to 0.5 V for example, you can choose a narrow range such as 0 to 0.01 V. 2. Each range is divided into a fixed number of steps: the resolution. The smaller the range and the greater the resolution, the more precise the reading. The 751-SG offers a choice of resolutions from 12-bit for fast sampling to 18-bit for greater precision. 3. You need to apply an excitation voltage which supplies sufficient current to keep all the bridge circuits energised. The 751-SG package provides excitation for each of 16 Wheatstone bridges. 4. Measured changes may not only be due to the changes in strain. Other factors might also affect the reading, such as a change in the excitation voltage. This is of especial concern in long-term measurements where component values may drift with time and temperature. With the 751-SG, when a bridge input is selected the Windmill Software automatically monitors the excitation voltage and performs the bridge calculation to produce a reading in microstrain. This eliminates errors due to changes in excitation voltage. 5. The changes in voltage due to strain are tiny: measured in microvolts. Monitoring such small signal changes can often produce jitter in the readings from noise. For slow sampling you can counteract this with an integrating analogue-to- digital converter. By averaging the signal over 50 or 60 Hz the noise is rejected. Analogue Inputs =============== You can configure each of the 751-SG's 16 analogue input channels to accept any of these inputs: - voltage - quarter bridge: single strain gauge - half bridge: tensile + compressive strain gauge - half bridge: normal + transverse strain gauge - full bridge: 2 tensile + 2 compressive gauges - full bridge: 2 normal + 2 transverse gauges - full bridge: tensile normal + compressive normal + tensile transverse + compressive transverse gauge Digital Inputs, Outputs and Counters ==================================== The 751-SG provides 32 digital I/O lines, arranged in four groups of 8. One group of 8 lines can also be used to count. Each counter starts at zero and counts pulses to a maximum of 65535. You can reset a counter at any time from Windmill software. You can use the counters in two modes: accumulating count and resetting count. In accumulating count the counter keeps counting until you reset it. In resetting count the counter shows the number of pulses since the last reading. Windows Software ================ Windmill Software is included in the 751-SG package. This modular suite offers data logging, charting, alarm monitoring, output control and real-time links to other applications like Excel. Windmill runs under Windows 10, 8, 7 64-bit and all other versions down to Windows 95. Technical Support ================= Should you need any advice on setting up your system we are happy to help by phone or e-mail. This unlimited service is included in the price and lasts a lifetime. For more information e-mail [email protected], telephone +44 (0)161 833 2190 or visit https://www.windmillsoft.com/daqshop/strain-measurement.html Further Reading =============== A tutorial on Measuring Strain is at http://www.windmill.co.uk/strain.html ________________________________________________________ ________________________________________________________ DAQ News Round-up ________________________________________________________ Welcome to our round-up of the data acquisition and control news. If you would like to receive more timely DAQ news updates then either grab our RSS newsfeed at https://www.windmillsoft.com/monitor.xml or follow us on Twitter at http://twitter.com/#!/DataAcquisition Sensors Harvest Energy from Vibration to Keep unning Tiny sensors can now harvest constant power from vibration instead of using batteries. MicroGen Systems and Cornell University have collaborated to develop battery-free sensors that can operate in anything that spins, rolls, jiggles or shakes, like car tires and clothing dryers. Source: Cornell University http://www.newswise.com/articles/ Measuring bacterial heat could reduce cost of diagnosing TB Researchers in Switzerland hope to reduce the time and cost of diagnosing tuberculosis by measuring the heat bacteria produce as they grow. A team is developing a method using microcalorimeters, which produce unique electrical signals based on the heat given off by different chemical, physical or biological processes. Source: The Engineer https://www.theengineer.co.uk/ Tests Help Ensure Reliable Wireless Alarm Beacons for First Responders Wireless emergency safety equipment could save lives-if signals are transmitted reliably. But few performance standards exist. Now, tests at the National Institute of Standards and Technology (NIST) are helping to ensure that alarm beacons for firefighters and other emergency responders will operate reliably in the presence of other wireless devices. Source: NIST https://www.nist.gov/pml/electromagnetics/wireless-081611.cfm Electronic 'tongue' could identify types of Cava Researchers at Universitat Autonoma de Barcelona have developed an electronic tongue which can identify different types of cava wines, thanks to a combination of sensor systems and advanced mathematical procedures. The device automatically produces classifications similar to those of a sommelier. Source: UAB http://www.uab.es/ ________________________________________________________ ________________________________________________________ Data Acquisition Exhibitions and Conferences ________________________________________________________ Our quarterly update of data acquisition and control exhibitions around the world. Automation Vietnam 15-17 September Hanoi Vietnam Automation and assembly technologies. Features technology presentations to impart new knowledge to participants. http://www.vietnammanufacturingexpo.com/ Automation 2011 20-23 September 2011 Mumbai India Factory automation, robotics, drives and controls, building automation and software solutions. It is termed as India's biggest Automation show of the year. http://www.iedcommunications.com/ Sensing Technology 27-28 September 2011 Birmingham UK Test, measurement, instrumentation. http://www.sensingtechnology.co.uk/ MESUREXPOVISION 2011 4-6 October 2011 Paris France France's research, testing and industrial instrumentation exhibition. http://mesurexpovision.com/ Smart Automation Austria 2011 4-6 October 2011 Linz Austria Trade fair for industrial automation. http://www.smart-automation.at/ CHEM-MED 2011 5-7 October 2011 Milan Italy Complete showcase of products, technologies, processes and instrumentation, including manufacturing and processing machinery, equipment and components; equipment, instrumentation and materials for the laboratory and process; testing, control and automation technologies and instrumentation. http://www.chem-med.it/ Controls Instrumentation and Automation 2011 22-25 November Singapore Showcases the latest technologies catering to the process engineering demands in the Chemical, Food, Petroleum/Energy, Waste and Water industries. http://www.cia-asia.com/ ________________________________________________________ ________________________________________________________ * Copyright Windmill Software Ltd * Reprinting permitted with this notice included * For more articles see http://www.windmill.co.uk We are happy for you to copy and distribute this newsletter, and use extracts from it on your own web site or publication, providing the above notice is included and a link back to our website is in place. An archive of previous issues is at http://www.windmill.co.uk/newsletter.html and an index of articles at http://www.windmill.co.uk/monitorindex.html Windmill Software Ltd, PO Box 58, North District Office, Manchester, M8 8QR, UK Telephone: +44 (0)161 833 2782 Facsimile: +44 (0)161 833 2190 E-mail: [email protected] http://www.windmill.co.uk/ https://www.windmillsoft.com/
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