The capabilities of today’s compact pressure transducers enable designers to improve the performance and engineering of machines across industry, says Mike Powers, Product Marketing Director for Gems Sensors and Controls.
The need to optimise industrial equipment and minimise maintenance is ever present and this is increasingly achieved by building in components that can protect and regulate engineering systems. Advances in the design and manufacture of pressure transducers have resulted in exceptionally high quality components with enhanced functionality that can withstand particularly aggressive process conditions, extremes of temperature, mechanical shock and vibration. As a result, pressure sensing components are a fundamental requirement of many industrial and process applications.
A pressure transducer converts pressure, typically that of fluid or gas, into an electrical output signal, offering the potential for sophisticated predictive control within a system. For example, a gradual decrease in pressure measured by a transducer might trigger a series of escalating alarm signals, allowing for appropriate action to be taken before the ultimate level is reached and an automatic shutdown is triggered.
Pressure sensors contain a thin sealed sensing element or diaphragm that is in direct contact with the pressure media. Displacement of the diaphragm thus causes the strain gauge to flex, either in compression or under tension, with the electrical output being directly proportional to the pressure or vacuum applied. Output from the sensor is connected to on-board electronics, with the entire unit being contained in a compact and sealed stainless steel housing that enables designers to specify transducers in a wide range of applications.
The latest pressure transducers comprise an extremely sensitive pressure sensing element combined with a sophisticated electronics package. The testing of these devices has resulted in some impressive statistics, measuring a response of 1ms or less to changes in pressure, accuracy with almost zero drift over time and an operating life in excess of 100 million cycles. Not only that, these pressure transducers can provide an exceptionally high degree of accuracy in aggressive environments. For example, Gems Sensors & Controls 3300 series pressure transducers are capable of operating over a temperature range of -40°C to +125°C, with stainless steel wetted parts that are capable of resisting harsh chemicals, while a strong and corrosion-resistant structure with low hysteresis and creep high is generated by the temperature vacuum brazing of the stainless steel components during sensor production.
Advances in electronics technology have allowed designers to make much greater use of pressure transducers. The integral electronic signal conditioning that has been supplied with these devices over recent years often incorporates advanced ASIC (application specific integrated circuits) technology, a factor that has opened up opportunities for many markets, since the performance and functionality of each transducer can be tuned to meet the specific requirements of each customer. The introduction of ASIC has, in many instances, also reduced the unit cost of transducers by a factor of 10; for example, the performance previously associated with units that sold for £300 can now be delivered from devices costing £30 or less.
Designers have made good use of pressure transducers in areas that are difficult and expensive to access. For example, an important role played by pressure transducers is in managing the pitch control system on wind turbines. Adjusting the pitch of the blade (the angle at which the edge of the blade cuts into the wind) as the wind speed changes not only ensures optimal turbine efficiency but also avoids damage. When the wind speed rises above the turbine’s rate capacity, it is the speed at which the blades can be edged parallel with the wind that determines whether such damage can be avoided. Transducers enable the swift response of the hydraulic pitch control, minimising damage to wind turbines and preventing costly maintenance and repairs.
The designers and developers of today’s pressure transducers have long been exercising their technological expertise to provide increasingly powerful solutions that offer great advantages to designers in the construction of custom engineered systems. As a result of this on-going development, sensor manufacturers have already tackled many of the issues that challenge a series of applications and a growing number of product solutions to these challenges are already available ‘off the shelf’. Personal attention and technical support is always available from the market-leaders when there is a need to produce bespoke systems to customers’ individual requirements but in many cases much time and money can be saved by taking advantage of these ‘off the shelf’ solutions.
The latest pressure transducers offer designers the potential to enhance a range of machines and systems, thanks to the extraordinarily high levels of performance achieved by recent advances in transducer technology.
Gems Sensors& Controls Inc.
One Cowles Road