Temperature effects on measurements can cause changes in what parameters?

• A. Only electrical noise
• B. Density, viscosity, and sensor output
• C. Only mechanical wear
• D. None of the above

Answer: (B)

Temperature changes affect measurement in two main ways: the properties of the measured medium and the response of the sensing system. For fluids, density and viscosity are both temperature-dependent. As temperature rises, many liquids become less dense and their viscosity typically decreases, which alters how they flow or behave in a measurement, such as flow or viscometry readings. At the same time, the sensor itself can drift with temperature because most sensors and their electronics have temperature coefficients. Thermal expansion, changes in resistance, and shifts in calibration all cause the sensor output to move even if the measured quantity is unchanged. Because temperature can change both the medium’s properties (density and viscosity) and the sensor’s output, the most complete description of what can be affected is density, viscosity, and sensor output.