October 29, 2021
The Sapphire wafers used in SOS technology are unlike the naturally occurring gemstones that are found in the ground. They are grown as a single gem in a highly controlled laboratory environment, ensuring no impurities or imperfections in the finished structure.
The crystal is then cut at roughly a 60° angle. This is what is referred to as the “r-plane”, a term used to define the angle of the gemstone cut.
This is where it gets really interesting… Because of the precise angle of the cut, Sapphire wafers have extra Oxygen atoms that almost mirror the spacing of Oxygen atoms found in the plane of Silicon. This incredible natural symmetry allows the Oxygen atom in the Silicon to bond to the Oxygen atom in the Sapphire, creating a Silicone-Oxygen, or SiO2 bond. It is this compatibility between the plane of Sapphire and plane of Silicon that enables the SOS technology.
An SOS structure is essentially a semi-conductive surface. It provides the base for circuit and sensor manufacturing that is durable, resistant to heat and radiation, and performs consistently under varying levels of stress.
A Wheatstone bridge is formed in the Silicon during the manufacturing process of SOS sensors. This is a circuit used to measure electrical resistance between the two “legs” of the circuit.
Strain Gauges are used in place of resistors to provide a “difference measurement”. So when the sensor is attached to the diaphragm it will be able to accurately indicate any strain change in the metal whilst pressure is applied. This can then be converted to a voltage change in order to transmit pressure data.
That, plus the insulating nature of the Sapphire base, protecting the strain gauges, and the lack of bonding agent between the two elements ensures a highly reliable and accurate sensor with minimal hysteresis under stress. The elasticity of the Sapphire element also provides the structure with great repeatability over an extended period of time.
It is for this reason the highly stable, highly accurate SOS sensor technology is a popular choice within aerospace and aeronautic applications.
So you see? It's not WITCHCRAFT at all... just some very clever SCIENCE!
October 15, 2021
ESI offers a selection of high temperature pressure transducers and transmitters that are best suited to environments where the media temperature exceeds normal limits – such as steam, metal work and industrial manufacturing, oil & gas, aerospace and automotive applications. But which transducer is right for you?...
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ESI are now offering a number of ranges that are compatible for Hydrogen based environments....
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ESI had the pleasure of providing help in the most unlikely of places recently when a local farmer contacted us after the automatic water feed experienced a malfunction. Due to a failure of a competitors pressure transmitter 30 cows were without refreshment in the height of summer!...