Transducer Element
Micromachined silicon membranes containing integrated resistor networks convert applied fluid or gas pressure into measurable electrical voltage changes. In solid state pressure sensors, a piezoresistive diaphragm flexes under physical force to induce mechanical strain directly across diffused or implanted semiconductor strain gauges. The device stops operating linearly when mechanical deflection exceeds silicon yield strength limits or when operating temperatures exceed semiconductor doping stability bounds.
Piezoresistive Conversion
Applied mechanical strain alters crystal lattice geometry, changing electrical resistivity within silicon strain resistors. Bending of a piezoresistive diaphragm stretches upper surface resistors while compressing lower surface resistors arranged in a full bridge circuit. This complementary resistance change yields an output voltage proportional to differential pressure.
Thermal Interference
Temperature variations induce thermal expansion stresses and modify carrier mobility inside doped silicon regions. Temperature shifts affecting a piezoresistive diaphragm alter offset voltage and span sensitivity, causing signal drift in uncompensated sensor circuits. On-chip compensation resistors reduce these thermal errors across specified operating temperature ranges.
Metrological Calibration
Automated calibration rigs apply precise pneumatic pressures to verify zero balance, linearity, and hysteresis across the full operating range. Factory qualification protocols evaluate each piezoresistive diaphragm by logging electrical output voltages against reference pressure standards traceable to national metrology institutes. Pressure sensing instruments meeting stated linearity tolerances receive calibration certificates specifying active temperature compensation parameters required for high accuracy field installation.
