Introduction
AMETEK Sensors and Fluid Management Systems is a leading provider of pressure sensors for aerospace applications, with a long history of manufacturing high-quality and reliable sensors for various applications. Our extensive experience includes measuring hydraulic fluid pressure in the Boeing 787 Dreamliner and measuring differential pressure across an engine inlet air filter on Airbus Helicopters.
AMETEK SFMS’s latest generation of pressure sensors use advanced Silicon-on-Insulator (SOI) technology and has accumulated extensive time on-wing, demonstrating reliability exceeding 200,000 hours MTBF in severe engine environments, and over 1 million hours in some airframe applications. SFMS’s pedigree with this specific SOI pressure sensing technology is impressive, with a list of customers and programs including CESA A400M, Safran Aircraft Engines LEAP-1A/B/C Engine, UTAS JSF F-135 Engine, Gulfstream G650, G500, G600, and more.
Our program team’s organization is well-structured, with an integrated product team assigned for each development program. The team comprises a team leader/program manager, project engineer(s), manufacturing engineer, quality engineer, purchasing/subcontracting representative, sales representative, and customer service representative. SFMS uses a proven program management approach to ensure a successful design that meets all program requirements.
Design Overview of Proposed Transducers
Pressure measurement is an important aspect of many Aerospace applications, and the accuracy of such measurements is critical. Our transducers provide an innovative design that offers thermal compensation and analog output while maintaining a small and compact design. The transducers are based on proven SOI pressure sensing technology, which offers high accuracy and stability, making them a reliable choice.
The principle of operation of the pressure transducers is based on SOI pressure sensing technology, which uses piezoresistive silicon strain gauges deposited onto a silicon diaphragm. The SOI chip deflects in proportion to the applied pressure, and the integrated strain gauge measures the displacement via changes in bridge resistance. The resulting signal is then proportional to the applied pressure. This design provides several advantages, including accurate performance at elevated temperatures, minimal risk, and proven high stability that can be demonstrated using test methods that duplicate actual operating conditions.
The transducers consist of four main component groups: the media-isolated SOI pressure sensing module, pressure fitting assembly, thermal compensation electronics, and case and electrical connector. The pressure sensing module comprises the SOI pressure-sensing die, Inconel or Stainless-Steel header with feed-through pins, silicone oil pressure transfer media, and an isolation diaphragm. The SOI wafer is a silicon substrate from which the pressure sensing dies are constructed, and it is diced into individual pressure sensing die using a selective etching technique. Unlike conventional diffused silicon wafers, the SOI wafer is comprised of three layers, including a P-type mono-crystalline layer of silicon onto which the piezoresistive strain gauges are etched, a base P-type silicon substrate, which is etched to create a diaphragm, and a dielectric layer of Silicon Dioxide (SiO2) that electrically insulates the mono-crystalline layer and substrate.
The absence of the P-N junction offers significant advantages, including the ability to operate at much higher temperatures, improved media compatibility, improved noise characteristics, and improved long-term stability. The pressure die is fabricated using a selective etching technique on the silicon substrate to simultaneously produce many diaphragms on a single wafer. The rectangular diaphragms convert pressure into strain.
AMETEK’s SOI technology and proprietary Field-Shield design ensures exceptional accuracy, reliability, and stability even in challenging environments. The unique Field-Shield eliminates the primary cause of long-term instability found in piezoresistive pressure transducers, particularly at high temperatures.
Learn more about Sensors here: https://www.ameteksfms.com/products/pressure-sensors
Conclusion
AMETEK Sensor and Fluid Management Systems pressure transducers offer a reliable and accurate solution for aerospace applications that require pressure measurement. The SOI pressure sensing technology used in the transducers provides high accuracy and stability, making it a proven choice for aerospace applications. Additionally, the compact design and thermal compensation with analog output make the transducers a versatile option for various applications.
For more Information contact:
