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Hollow-shaft absolute encoders
:New
equipment
of interest and can then read directly the exact temperature at that point. A built-in 3.5 in disc drive allows storage and recall of up to four separate images which may be displayed individually or side-by-side. This technique is useful for comparing temperature profile variation with time over the whole image or at any point on the image. It incorporates auto-focus, auto-sensing and auto level control, and a G PI B interface allows the system to communicate direct with a PC. The detector/camera unit weighs 3.5 kg and measures 135 x 159 x 228mm. A wide range of optional accessories includes lenses, filters and carrying cases. Lambda Photometrics Ltd., Lambda House, Batford Mill, Harpenden, Herts AL5 5BZ, UK
Hollow-shaft absolute encoders Absolute hollow-shaft encoders are available from Baumer Electric. The new BFO and BFU encoders are suitable for use where rotary motion needs to be
monitored. The devices work by producing a signal in relation to an absolutely defined fixed point so allowing accurate positioning immediately after power up or power failure. Since the controller does not have to be reset via a reference pulse for orientation, high accuracy operations in both industrial and robotic applications can be achieved. Absolute encoders can offer a high degree of security, necessary in certain applications such as complex integrated systems. Straightforward mechanical mounting, through the hole in the centre of the housing unit, eliminates the need for fitting and adjustment. The BFO type encoder may be used for end of shaft positioning, while the BFU type may be positioned at any point along the motor shaft length. Neither require internal or external flexible coupling between the transducer and drive. The compact housings, measuring 60mm x 60mm x 30mm (or 40 mm), enable the encoders to be used in areas where conventional rotary encoders are too large. The nine-bit output signal is available in either decimal-code BCD, natural binary-code or
Absolute hollow-shaft encoders from Baumer Electric provide high accuracy operation
NDT& E International
June 1991
Gray-code, providing secure transmission. By means of an external strobe signal the angular position of the BCD or binary encoder can be latched at any time so that information can be temporarily stored and retrieved later. The shaft hole has a diameter of up to 12 mm,with smaller dimensions available on request. Rotational speeds of up to 12 000 rpm mean the encoders have a wide application. Baumer Electric Ltd, Units 33-36, Shrivenham Hundred Business Park, Majors Road, Watchfield, Swindon SN6 8TZ, UK
Storage tank corrosion monitoring service A single isolated corrosion pit only a few mm in diameter can lead to perforation of the floor of an oil or gas storage tank. With tank floors having a surface area of typically 2000 m2 the task of identifying isolated potential failure sites is clearly a difficult one. In principle, ultrasonics should be the ideal method of inspection because ultrasonic examination can provide quantitative data on the location and extent of corrosion damage. In practice ultrasonic techniques are rarely favoured because the presence of plate inclusions can mask the signals from the corrosion pits. As a consequence detection of isolated pitting can be like looking for a needle in a haystack. On top of this, application of ultrasonics is generally too time-consuming to be competitive with methods such as magnetic flux leakage. The Technology Centre of Babcock Energy claim to have solved these problems by using Tankscan, which is a reconfiguration of the automated ultrasonic inspection system developed by them and extensively proven for highly reliable inspection of critical components for the nuclear
173
equipment
of interest and can then read directly the exact temperature at that point. A built-in 3.5 in disc drive allows storage and recall of up to four separate images which may be displayed individually or side-by-side. This technique is useful for comparing temperature profile variation with time over the whole image or at any point on the image. It incorporates auto-focus, auto-sensing and auto level control, and a G PI B interface allows the system to communicate direct with a PC. The detector/camera unit weighs 3.5 kg and measures 135 x 159 x 228mm. A wide range of optional accessories includes lenses, filters and carrying cases. Lambda Photometrics Ltd., Lambda House, Batford Mill, Harpenden, Herts AL5 5BZ, UK
Hollow-shaft absolute encoders Absolute hollow-shaft encoders are available from Baumer Electric. The new BFO and BFU encoders are suitable for use where rotary motion needs to be
monitored. The devices work by producing a signal in relation to an absolutely defined fixed point so allowing accurate positioning immediately after power up or power failure. Since the controller does not have to be reset via a reference pulse for orientation, high accuracy operations in both industrial and robotic applications can be achieved. Absolute encoders can offer a high degree of security, necessary in certain applications such as complex integrated systems. Straightforward mechanical mounting, through the hole in the centre of the housing unit, eliminates the need for fitting and adjustment. The BFO type encoder may be used for end of shaft positioning, while the BFU type may be positioned at any point along the motor shaft length. Neither require internal or external flexible coupling between the transducer and drive. The compact housings, measuring 60mm x 60mm x 30mm (or 40 mm), enable the encoders to be used in areas where conventional rotary encoders are too large. The nine-bit output signal is available in either decimal-code BCD, natural binary-code or
Absolute hollow-shaft encoders from Baumer Electric provide high accuracy operation
NDT& E International
June 1991
Gray-code, providing secure transmission. By means of an external strobe signal the angular position of the BCD or binary encoder can be latched at any time so that information can be temporarily stored and retrieved later. The shaft hole has a diameter of up to 12 mm,with smaller dimensions available on request. Rotational speeds of up to 12 000 rpm mean the encoders have a wide application. Baumer Electric Ltd, Units 33-36, Shrivenham Hundred Business Park, Majors Road, Watchfield, Swindon SN6 8TZ, UK
Storage tank corrosion monitoring service A single isolated corrosion pit only a few mm in diameter can lead to perforation of the floor of an oil or gas storage tank. With tank floors having a surface area of typically 2000 m2 the task of identifying isolated potential failure sites is clearly a difficult one. In principle, ultrasonics should be the ideal method of inspection because ultrasonic examination can provide quantitative data on the location and extent of corrosion damage. In practice ultrasonic techniques are rarely favoured because the presence of plate inclusions can mask the signals from the corrosion pits. As a consequence detection of isolated pitting can be like looking for a needle in a haystack. On top of this, application of ultrasonics is generally too time-consuming to be competitive with methods such as magnetic flux leakage. The Technology Centre of Babcock Energy claim to have solved these problems by using Tankscan, which is a reconfiguration of the automated ultrasonic inspection system developed by them and extensively proven for highly reliable inspection of critical components for the nuclear
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