The performance stability of an instrument is often assessed by which parameter?

The performance stability of an instrument is primarily assessed by linearity, which refers to the ability of the instrument to produce outputs that are directly proportional to its inputs across the entire measurement range. A linear response ensures that as the input increases or decreases, the output maintains a consistent relationship, which is vital for accurate and reliable measurements. If an instrument is linear, it indicates that its performance is stable throughout its operational range, meaning variations in measurements are due to actual changes in the measured parameter rather than inconsistencies in the instrument itself.

While response time, maximum deviation, and dynamic range are important characteristics of an instrument, they do not directly evaluate its performance stability in the same manner as linearity. Response time measures how quickly an instrument reacts to a change, maximum deviation indicates the largest difference from a true value, and dynamic range refers to the range of values an instrument can accurately measure. Nevertheless, linearity focuses specifically on how stable and predictable the outputs are across a range of inputs, making it the most relevant parameter for assessing performance stability.