#2 Weekly application: iron in water

Let’s delve into the fascinating world of color measurement in water using the Platinum-Cobalt (Pt-Co) scale 🌊🌈

The Pt-Co color scale measures the “yellowness” of a liquid. It was introduced in 1892 by chemist Allen Hazen and is also known as the APHA/Hazen scale. This scale evaluates pollution levels of iron or manganese in water or wastewater.

How It Works:

  • A value of 0 on the scale corresponds to distilled water (white), while a value of 500 indicates distinctly yellow water.
  • The Pt-Co scale is widely used in various industries, including water, wastewater treatment and the chemical industry.



  1. Compliance: Helps adhere to industry standards.
  2. Consistency: Maintains quality across different batches.
  3. Precision: Informed decisions based on accurate color measurements.

For more details, you can explore Kemtrak’s application note on the Kemtrak platinum-cobalt color analyzer. Stay tuned for the next exciting application!