Determining Accelerometer Zero Offset Errors during Bench Calibration
Static multi-position gravity inversion separates zero-g offset from scale factor while Allan variance bias instability defines maximum valid integration time.
Invar Mounting Plate
Dimensional Stability
Thermal expansion management defines the purpose of an invar mounting plate in precision optical and electronic assemblies. This low expansion nickel-iron alloy component supports sensors or laser resonators to maintain spatial alignment despite temperature fluctuations. The plate acts as a physical reference plane where the base material coefficient of expansion reaches values as low as one point two parts per million per degree Celsius.
Material Properties
High nickel content provides the characteristic stability observed in this metal. Heat absorption does not trigger the atomic lattice movement found in standard steel or aluminum alloys. Designers specify this part when sub-micron tolerance requires immunity to ambient heat cycles.
Installation Requirements
Mechanical fastening onto the invar mounting plate necessitates careful selection of mounting hardware to prevent strain transfer. Steel bolts possess a higher expansion rate, which creates localized stress if the interface between the components lacks flexibility. Belleville washers or slotted holes mitigate the risk of mechanical deformation during thermal cycling.
Verification Protocol
Calibration facilities confirm the flatness and parallel geometry of the surface using laser interferometry or coordinate measuring machines at controlled reference temperatures. Any deviations recorded during these scans identify potential residual stress from the machining process. These measurements ensure that the component maintains structural integrity within its operating range.