A programmable liquid sampler for obtaining and digitally analyzing multiple, sequential samples in real time from an external source of liquid to be analyzed comprises an adaptive feedback algorithm for correcting sample weight measurements occasioned by vacuum delays. A sampling assembly receives and at least temporarily stores a sample drawn by suction through an air port that can also pressurize the chamber. A load cell determines sample mass through a logic controller that implements adaptive feedback by recognizing a desired target sample size, requesting an initial sample, and measuring the initial sample size. A variable scaling factor is derived by comparing the target sample size to said measured sample size and the subsequent requesting size is scaled. Samples can be stored in multiple compartments of a radial table that is indexed by the computer software for proper sample control.