Social & Preventive Medicine Estimation of free chlorine of water is done by: March 2012, March 2013 (c, g) A Ohotolidine test B Horrock's apparatus C Paterson's chloronome D Kata thermometer 💡 Explanation Estimation of free chlorine of water is done by: March 2012, March 2013 (c, g) ✓ Correct Answer: A. Ohotolidine test