OpenSource Turbidimeter

Design Goals

  1. Turbidimeter costs less than $100 (for a production model),
  2. Reads samples with an accuracy of 0.05 NTU in the sample range 0-5 NTU, and 0.2 NTU in the range of 5-20 NTU,
  3. Reads samples with an accuracy of 5% in the range 20-1000 NTU,
  4. Can be operated manually, or in automated mode for continuous sampling,
  5. Transmits data to an Android phone, via USB connection or Bluetooth,
  6. Is powered by 2-4 AAA batteries,
  7. Can collect samples, automatedly, every 15-minutes for one month without needing new batteries.

Development Blog→

Why Do It

Our hope is that by proliferating low-cost sampling technology like this turbidimeter, engineers, funders, and community technicians will be able to get a clearer picture of the areas they serve, enabling them to make better decisions and respond more quickly to problems as they arise.

Related Resources

EPA Clean Water Act Approved methods
EPA Nephelometry Standards
Explanation of EPA/ISO standards


Open Turbidimeter Project on Launchpad (this is where all the project info & bug reports live, and the most recent code).


Chris Kelley
Alex Krolick
Clayton Grassick
John Feighery
Yoni Saltzman