This article from Gems Sensors & Controls explains how the latest-generation pressure transducers, combining extremely sensitive pressure sensing with sophisticated electronics, enhance the performance of pressurised systems.
Pressure transducers have become an invaluable tool for the protection and optimisation of industrial equipment, converting fluid pressure into variable electrical signals that can play a vital role in monitoring and controlling a system.
Nevertheless, while existing transducers offer impressive performance, there is an ever-increasing level of accuracy in the output of these components thanks to the new methods in which sensor elements and electronics packages are constructed.
These new methods have not only added functionality to pressure transducers, but they have also enabled the components to withstand particularly aggressive process conditions, such as extremes of temperature, mechanical shock and vibration. The latest pressure sensors from Gems Sensors and Controls combine an extremely sensitive pressure sensing mechanism with a sophisticated electronics package.
The transducers can therefore respond to changes in pressure in 1ms or less, offer accuracy with almost zero drift over time, and achieve an operating life in excess of 100million cycles. Their resilience and sophistication are the result of some highly innovative and carefully controlled methods of construction; in particular, the advanced strain gauge technologies of sputtered thin film and chemical vapour deposition (CVD).
Benefits of CVD
CVD is highly effective in the manufacture of strain gauge sensors, which detect movement in a pressure diaphragm and convert the information into electrical signals. Devices manufactured using CVD are typically compact and extremely accurate, with excellent hysteresis characteristics.
The sensors are produced on wafers in large batches, using polysilicon deposited on a stainless steel substrate, with the strain gauge patterns being chemically milled.
Sputtered thin film technology has also been integral to the success of the latest fluid pressure transducers. Sputtering is a process whereby a solid target material is bombarded by energised particles, causing it to release atoms. Sputtered thin film deposition is a method of forming a thin film from the released atoms.
The application of the sputtered thin film process during the manufacture of pressure transducers results in a sensitive, robust diaphragm that is suitable for direct contact with almost all liquids and gases.
Allied to these innovations in the chemical manufacture of pressure sensors have been some equally valuable advances in electronics, which have greatly enhanced the capabilities of transducers. For example, the electronic packages that have been supplied with pressure transducers over recent years have enabled each sensor to be tuned to meet the specific requirements of the customer. These packages incorporate advanced ASIC (application-specific integrated circuit) technology, which enhances performance and functionality. They can also be customised; this is a convenient and effective option that cuts costs when expensive and complex control technology is not needed.
Indeed, the economic advantage of introducing ASIC-based devices has been significant; combined with improvements in volume manufacturing techniques, the introduction of ASIC technologies has, in many instances, reduced the unit cost of transducers by a factor of 10, enabling manufacturers to sell at approximately £30 a sensor that offers a level of performance previously associated with units that sold for £300.
CVD and sputtered thin film technology, combined with ASIC electronics, offer a powerful combination of accuracy and reliability to the increasing number of engineers who choose to investigate the advantages of pressure transduction technology.
The broad range of sensor products now available will enable engineers to apply transducers within ever more challenging environments, as will the modular nature of the components, which increases the number of options available for accommodating transducers. As they continue to develop and improve, pressure sensors will exercise a greater level of data acquisition and system control within the many industries that now employ them and within those that will adopt them in the future.
3300 series pressure transducers
Gems Sensors and Controls 3300 Series pressure transducers possess a wide range of outputs, electrical connections and pressure ports, with a broader choice of pressure ranges for 2011 covering 0 to 600psi (0 to 41bar), and are capable of operating over a temperature range of -40 to +125degC. They also provide a long operating life with excellent resistance to pressure shocks and mechanical vibration, while the high-temperature vacuum brazing of the stainless steel components during sensor production offers a strong and corrosion-resistant structure with low hysteresis and creep.
Follow the link for more information about the 3300 Series pressure transducers from Gems Sensors and Controls.