The expense of sophisticated research-related sensors and tools has often limited their adoption to a
select, well-funded few. This paper provided a methodology for applying the FOSS approach to design
and development of an open-source colorimeter; a methodology that eliminates cost as a barrier to
adoption and makes the tool available to the broadest possible audience. The performance of the tool
produced by this methodology was successfully demonstrated against a much more costly commercial
product. An open-source 3-D printable solution for colorimetric determination of COD was successfully
demonstrated and the design is now freely available for reuse, derivation and modification.
The outlook for development of scientific-grade instrumentation utilizing the FOSS approach is
extremely promising. Inexpensive open-source 3-D printers and free software have put one-off production
of highly specialized tools within the grasp of the end user, bypassing historically expensive design and
manufacturing steps. Perhaps more importantly, these technologies and methodologies promise heretofore
unheard of access to sophisticated instrumentation by those most in need of it, under-developed and
developing world laboratories.