Isolation Membrane
A thin metallic barrier protects sensitive internal pressure sensing elements from direct exposure to corrosive process fluids. Industrial pressure transmitters incorporate a hastelloy c 276 diaphragm to maintain physical separation between hostile process chemicals and internal fill oil. The metallic foil deforms elastically under applied fluid pressure, transferring force to the internal hydraulic system without introducing static hysteresis.
Material selection bounds the operating environment, defining fluid compatibility limits for acids or wet chlorine gas.
Corrosion Resistance
Nickel-molybdenum-chromium alloys exhibit resistance to localized pitting and crevice corrosion in aggressive chemical environments. Exposure to hot contaminated mineral acids highlights the durability of a hastelloy c 276 diaphragm compared to standard stainless steel alternatives. Chemical plants rely on this alloy structure to prevent process fluid ingress into sensor electronics.
Mechanical Rigidity
Thick membranes increase structural stiffness, reducing sensitivity to low-range pressure fluctuations. Thin foils improve lower limit response but increase vulnerability to mechanical overpressure damage.
Weld Integrity
Hermetic perimeter sealing prevents process fluid leakage around the edge of the isolation foil. Electron beam welding secures the metallic membrane to the housing body under controlled atmospheric conditions. Verification testing uses helium mass spectrometry to detect micro-leaks along the weld seam before sensor assembly.
