Thermal Distribution
Variations in temperature across the physical dimensions of a component or assembly can lead to localized mechanical stress and sensor instability. When spatial temperature gradients are present, the front and back of a sensor housing may expand at different rates. This non-uniform heating is a common source of measurement bias.
Driving Source
Heat generated by internal electronics or exposure to external sunlight creates these uneven profiles. In the presence of spatial temperature gradients, a single temperature sensor on the board might not represent the temperature of the sensing element. This leads to poor compensation.
System Impact
Structural warping caused by these differences can misalign the sensitive axes of an inertial unit. For example, spatial temperature gradients in an accelerometer package can shift the proof mass. This shift is interpreted by the electronics as a change in acceleration.
Designers use thermally conductive materials and heat spreaders to equalize the temperature across the device. Minimizing these gradients is especially important for devices that must operate in uncontrolled outdoor environments. Rigorous testing involves mapping the temperature at multiple locations during a thermal cycle.
Design Goal
Creating a thermally isothermal environment is a primary goal for high-precision instrument design. Reducing spatial temperature gradients directly improves the repeatability of the sensor calibration.
