Oil Cavity Volumetric Expansion Mitigation in Piezoresistive Transducers
Minimizing fluid volume below five microliters and matching diaphragm spring rate eliminates thermal zero shift in isolated piezoresistive pressure cells.
Fluorosilicone Oil
Chemical Fill
A synthetic liquid medium combines the thermal stability of silicones with the chemical resistance of fluorocarbons. In pressure transmitter applications, fluorosilicone oil serves to transmit force from the isolating diaphragm to the internal sensing chip. Its low compressibility and high density make it suitable for a wide range of industrial environments.
Temperature Performance
The viscosity of this fluid remains relatively stable across a broad temperature range, which helps maintain consistent response times in outdoor transmitter installations. At very low temperatures, standard oils can become too thick and slow down the transmitter, while at high temperatures they can lose viscosity. This fluorinated compound prevents these extreme changes, allowing the sensor to operate reliably in cold climates.
This stability ensures that the transmitter maintains its response speed without lagging during rapid temperature changes.
Material Compatibility
Chemical compatibility prevents this oil from reacting with aggressive chemicals, solvents, and fuels that might penetrate the primary isolating diaphragm. If a pinhole leak occurs in the metal membrane, the chemical resistance of the fill fluid prevents rapid degradation and sensor failure. It is also compatible with common elastomer seals, reducing the risk of seal failure and fluid leakage over time.
Pressure Behavior
Under high static pressure, the fluid resists volume changes and gas absorption, ensuring that pressure is transmitted with minimal delay. This stability is critical for differential pressure measurements in high-line-pressure applications, where any changes in fluid volume can cause zero shifts. Engineers verify this behavior by monitoring the sensor output during static pressure cycles in a laboratory.