Stability Verification
Reliability procedures assess the long term stability of sensor outputs by simulating extended operating durations through elevated environmental stressors. In accelerated drift testing, components undergo exposure to high temperatures or humidity to predict how a signal offset evolves over years of service. This methodology isolates the electrochemical or mechanical changes that cause a sensor to deviate from its initial calibration.
Stress Application
Thermal cycling and constant high temperature soak periods represent the primary mechanisms for inducing premature aging. When a device enters the chamber, the technician monitors the zero point output at specific intervals to map the rate of change. Higher temperatures speed up the diffusion of contaminants or the relaxation of internal stresses that would otherwise require months to appear.
Degradation Curve
Data collected during these cycles allows for the calculation of an acceleration factor based on the Arrhenius equation. By comparing the drift observed at eighty five degrees Celsius to the expected drift at room temperature, engineers establish a mathematical model for sensor longevity. The resulting curve indicates when a component likely exceeds its specified accuracy limits under normal conditions.
Qualification Boundary
The validity of the test depends on the stress levels remaining below the material destruction point. If the temperature exceeds the glass transition temperature of a polymer housing, the resulting data fails to represent real world aging. Successful completion ensures that a batch meets the lifetime stability requirements defined by the original equipment manufacturer.
