Does orthotolidine test include Combined Chlorine?

[Ronald U.]

Am I understanding correctly that Orthotolidine colorometric test gives me Total Chlorine (FC + CC)? That would explain this morning's results:
Ortho. Chlorine Test 3.5
FC 2.0
CC 1.0
TA 90
CH 300
Borate 40
CYA 40
Thank you. Regards.

 

[JoyfulNoise]

The OTO test typically develops its full color over time. The initial color you'll see is FC and then it darkens to give you TC. I don't use the OTO chemistry because I have never gotten accurate results from it. It's best to think about it as a "presence of chlorine" test than any kind of accurate measure.

 

[Ronald U.]

Thank you, sir.