Given two measurements $\overline{x}_1$ and $\overline{x}_2$ with standard uncertainty $u_i$. The measurement uncertainty states that with a probability of $\approx 68\%$ the conventional true value of the measurand is inside the confidence interval: $$\overline{x}_i \pm u_i$$
How to answer whether both measurements $\overline{x}_1$ and $\overline{x}_2$ target the same measurand, i.e., they measured the same quantity?
EDIT 1: By uncertainty, I mean a standard uncertainty, e.g., obtained by following the GUM and use a Type B evaluation. Moreover, I am not interested in a new estimate from both measurements.
EDIT 2: Am I thinking wrong, or is the question wrongly stated? Or is the question only to be answered if the sample size/number of indications of both measurements is known?