Contamination of successive samples in portable pumping systems

Abstract

Automatic discrete sample pumping systems used to monitor water quality should deliver to storage all materials pumped in a given cycle. If they do not, successive samples will be contaminated, a severe problem with highly variable suspended sediment concentrations in small streams. The cross-contamination characteristics of two small commonly used portable pumping samplers are compared to each other and to reference measurements under conditions of sudden and severe changes in suspended sediment concentrations. The pressure-vacuum sampler showed greater cross contamination, especially when changing from high to zero concentrations, than the peristaltic sampler. Both samplers, however, cross-contaminated to some degree. The contamination was primarily due to the sand size particles rather than to the finer sizes

Citation

Thomas, Robert B.; Eads, Rand E. 1983. Contamination of successive samples in portable pumping systems. Water Resources Research 19(2): 436-440.