Introducing the concepts of measurement accuracy and precision in the classroom

Abstract

This work proposes simple experiments to introduce some fundamental concepts of the measurement area. It associates theory and practice through a strategy where the students create a real temperature data set with an Arduino board and three LM35DZ sensors and later use mathematical software to identify theoretical concepts as measurement accuracy and precision.

Physical Analysis of a Waterproof Temperature Sensor Responsiveness for Agricultural Applications

“…The uncertainty was at 0.26ºC, which is small and indicates a good sensor accuracyThe accuracy and precision can vary slightly according to each sensor piece, but they must keep in the same order of magnitude. This sensor presented a very good level of accuracy and precision, and it is interesting to emphasize that, sensors with good precision allows a later mathematical data correction with a simple addition, which isn't possible for sensors with poor precision (Martins 2019). For example, if all the measured values in the figure 5 (red line) were added by 0.26 (uncertainty value), then almost of them would have the same value of the true measured phenomenon (blue line).…”

“…Curiously, both concepts are only qualitative (Martins, 2019;JGCM 2012;De Bièvre 2012;Wallard 2012) and the accuracy is quantitatively associated with a parameter called uncertainty that is defined as T±, where T is true phenomenon value and  is a maximum difference between the sensor response and the true phenomenon value, while the precision is a variability numerically associated with the Standard Deviation or the coefficient of variation of several measurements under the same conditions.…”