Abstract This study focused on measurement system analysis MSA through gage of Repeatability and Reproducibility R&R methods (Average and Range Xbar/R, Analysis Of Variance ANOVA, Evaluating Measurement Process EMP III) to verify the accuracy and precision of a laser diffraction particle size analyser used to monitor particles’ size in wet grinding process, this device gained great faith in many researches without checking its fidelity. The initial evaluation demonstrates the measurement system’s unacceptability, driving to establish an improvement plan including preventive maintenance scheduling for the instrument to maintain it in good working conditions and anticipate futures anomalies that could affect the measurement system fidelity, standardization of measuring process by the instrument to reduce repeatability, which was found to be the largest source of variation in the gage R&R analysis affecting measurement accuracy and precision, along with unifying the method of calculating solid rate percentage of samples before measurements because it is a significant factor that can affect the measurement results, finally, operators training to conduct measurements in the same way and following unified procedures in the purpose of minimizing reproducibility and increasing the measurement system fidelity, which is proven by the final results. Along this evaluation, a critical comparison between these techniques is conducted in terms of calculations, result’s interpretation and acceptability requirements to evaluate the efficiency of each method. Xbar/R and ANOVA demonstrate a similarities in interpretation and acceptability criteria but ANOVA surpassed Xbar/R by adding new factors in the calculations, while EMP III, which is not widely addressed in the literature, shows a great difference with a distinguished methodology, distinct metrics and acceptability guidelines. Therefore, a combination of ANOVA and EMP III in measurement system analysis would be very effective by extracting comprehensive informations about the studied instrument. 
Read full abstract