Uncertainty estimation of a liquid flow standard system with small flow rates

•Jones method provided u(t) larger than ISO 4185 A.1.2 did by 4–10 times.•Correlation coefficient between ε and ρ was ca. 0.67 with little influence to U(Q).•uA(Q) became comparable with u(t) as t was increased to measure volume flow rate.•CMC could be declared from the uncertainty distribution as a function of flow rate.•CMC was (0.10–0.52)% (k = 2) when W was collected up to 10,000g.