Stable isotopes of the water molecule have emerged as powerful tracers
of the sources and trajectories of water leading to precipitation, at
different spatial and temporal scales. However, the high cost of
commercially available rain samplers for isotopic analysis, have made
using them for high spatial resolution networks and for studies being
conducted in developing countries prohibitively expensive. We have
designed a low-cost, simple, and robust rain sampler capable of sampling
precipitation for isotopic analysis on the event and monthly scale,
based on the existing designs provided in the literature. The event rain
samplers were tested to determine the minimum amount of rainfall to
minimize isotopic fractionation, both from post-sampling evaporation and
equilibration. These new rain samplers will enable isotopic sampling of
precipitation at high spatial resolutions. All the instructions for
constructing and using these samplers are made openly accessible to the
scientific community so they can easily be repeated and adapted to the
needs of each project. This open access and low-cost methodology will
help democratize the use of isotopes for hydrological studies in
developing countries.