A new method has been developed to reduce uncertainty in measuring the movement of structural members in high-temperature environments. The method involves using two measurement cables with different thermal expansion coefficients, placed in close proximity to the target and connected to the same sensors.
The difference in displacement measurements between the two sensors is not affected by the target’s motion, but rather by the relative thermal expansion of the cables. This allows researchers to estimate the thermal expansion of each cable and correct for its effect on the measurement.
The method has been successfully implemented using silicon-carbide and aluminum-oxide fibers, and has been shown to reduce measurement uncertainty by more than 90% compared to traditional methods. This could significantly improve the accuracy of structural fire testing and other high-temperature measurements.
The new method is currently being used in the NIST National Fire Research Lab, and could potentially be applied to other high-temperature measurement scenarios where thermal expansion of measurement cables is a concern.
Keywords: wires, thermal expansion, sensors, temperature profile, measurement uncertainty
