Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

pH, Free Chlorine and Total Alkalinity Sensors

pH, Free Chlorine and Total Alkalinity Sensors

pH, Free Chlorine and Total Alkalinity Sensors

Looking to play around automating my hot tub chemicals. Does anyone know of good, cost effective methods to sense pH, Free Chlorine, and Total Alkalinity that would give a 4-20 mA Output?


RE: pH, Free Chlorine and Total Alkalinity Sensors

pH is no problem. FC and TA are another issue. If you are not using CYA in the hot tube you can use an ORP probe to measure the free chlorine. To the best of my knowledge there are no TA probes, most TA instrument rely on titration. In any case any of these options are not cheap. The pH and ORP probes will probably run $1000 to $1500 each.

RE: pH, Free Chlorine and Total Alkalinity Sensors

Awesome thanks! I'm thinking I should be able to infer alkalinity based on pH changes after adding acid and corroborating with some manual measurements at the beginning. Good enough for what I'm using it for anyways.

Do you happen to know of any good brands for pH and chlorine?

Thanks again!

RE: pH, Free Chlorine and Total Alkalinity Sensors

Here I found many topics regarding pH measurement. This link is for common mistakes, but it is linked to many devices, which I believe was your question. I saw another article in the site on how to change voltage signals into Ampers, but I cannot find it. https://visaya.solutions/article/common-errors-ph-...
I think if you directly ask to these guys they might help: https://www.thermofisher.com/us/en/home/life-scien...

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close