microstrain

Microstrain is a unit of strain equal to one part per million (1e-6). In materials science and engineering, strain represents the fractional change in length a material experiences under load; microstrain quantifies very small deformations. For a bar of length L, a microstrain corresponds to a change in length ΔL = εL with ε = 1e-6, so a 1 m specimen would change by about 1 micrometer for each microstrain. In percent terms, 1 microstrain equals 0.0001 percent.

Microstrain is commonly encountered in structural health monitoring, materials characterization, and precision metrology. It is typically measured with strain gauges or fiber-optic sensors, as well as optical or interferometric methods, which can resolve small changes in length. In many applications, microstrain-level measurements are integrated into data acquisition systems that track load, temperature, and vibration.

MicroStrain, Inc. is a technology company that markets inertial sensors, wireless sensing platforms, and related data logging and processing software under the brand MicroStrain. The term microstrain also commonly appears as a unit of measurement in engineering literature and standards when describing small deformations, often in relation to sensors and structural health monitoring.