OTO test for chlorine, I am quite confused. Help.

[SPP]

Gentlemen,

I have the Pentair OTO test kit for chlorine. It comes in a blue box, 5 bottles of solution. Chlorine test, PH test, TA test, acid demand. It has a chlorine neutralizer labeled as bottle #3.

The chlorines test solution is the one needing 5 drops to create yellow solution if there is chlorine.
What confuses me and I been reading TPF stickies and doing search is :
"OTO can only measure Total Chlorine" this is the common information on OTO in most website

However in my test kit, it mentioned that the Chlorine test solution is for Residual Chlorine.
English is not my first language but "residual" sounds like "left over" and I been assuming that I am reading the "left over" of chlorine that will do sanitizing work or Free Chlorine. This is what I have been thinking all along.

So I did a search again and again.
I look at the FAQ in PoolCenter.com

LOOK AT 10th LINE FROM BOTTOM

and it says, OTO test only Free Chlorine.

Prior to using this 5 bottles Pentair, I once used a 2 bottle type Taylor ( I am quite certain ) that only test for CL and PH.
I recalled that I was able to read FC and TC by waiting 2 minutes or so, something like that. The bottle was also labeled OTO and the color to see for chlorine is also yellow and there is no second solutions for chlorine test, the other one is for PH.

So what is the real meaning of my OTO test kit by Pentair when it says RESIDUAL CHLORINE ??
I been searching Pentair website and could not get even a data to confirm what the test kit really read.

Most grateful.

Yes, I have ordered the TP-100 test kit....yipee


EDIT-EDIT Additional Info
The info in poolcenter.com is misleading, here is another link that now says OTO is for Total Chlorine only.
Look at the paragraph LIQUID KITS



Regards,
SPP

 

[JasonLion]

The standard OTO test, add drops to give shades of yellow compared to a color standard, measures total chlorine.

There is a trick you can do if you are fast and good at distinguishing colors. The OTO test will actually show the free chlorine level for several seconds before shifting to show the total chlorine. However, most people can't reliably read the colors quickly enough. Most people can't get be sure of the colors beyond the fact that the color was or was not changing before it settled down.

 

[duraleigh]

SPP,

"Residual" roughly means "left over".....as in a math equation......7/3 = 2 with a residual of 1.

For our purposes, it is the chlorine level that REMAINS in your pool.

It is still TC.

 

[SPP]

:lol: thanks guys...residual is TC..make sense....

Oh, I don't think I can see the color difference that fast Jason...you are right.

Well soon it will be over once my test kit arrives....