Type A method is the GUM-adopted technique for evaluating the uncertainty of repeated observations. Unfortunately, the Type A method cannot provide any information about the dispersion of identical observations. This article introduces a reasonable approximation for the uncertainty of identical observations depending on the resolution of the limited-resolution measuring device and the number of identical observations. The proposed approach reduces the estimated uncertainty by at least 13.7% of the instrument's resolution compared to the GUM method without sacrificing reliability. Moreover, the proposed approach is simple, straightforward, and easily implemented in daily routine work.
Monte-Carlo simulation was performed to compare the proposed uncertainty statement of identical observations against the conventional Type A uncertainty of the observations indicated by finer-resolution devices. The simulation revealed that the percentage of agreement does not drop below 70% at worst according to the strictest criterion; for round-robins' criterion, the agreement remained above 99%.