Need help/info on Swimming Pool Electronic Chlorine Tester.

[Richandmaria]

I have designed many processor based projects (RF and standalone controller) , but I need help with this one as I no very little about chemistry and I believe this has to be known to do this.
Measuring Pool PH is easy as I have found many Circuits that do this electronically. Measuring the level of Chlorine in a pool seems to be always done using a comparison method ( pool tester with chemicals) I have not found an inexpensive “electronic” method. I am willing to give up some accuracy as this will be used as a early warning system. As my project is to place this device in the pool water, Battery life will be an issue as well, but those things I know I can solve.
Thus in a nut shell I would like information on a circuit that converts the Pool chlorine amount to a electronic voltage.

Any information on this will help.

 

[stevez]

I did a little reading on pH measurement. I was left with the impression that while the electronics end is somewhat straightforward the construction of the probe is a challenge. Apparently a special glass is used that is porus to hydrogen ions - which is what pH is based on.

It sounds like you need info on a sensor that reliably indicates chlorine levels. While I have not done a search for such a sensor I'd scan the pool shops - especially the ones that cater to the upscale crowd. If a sensor existed that was priced even at the high end of consumer range then it's likely that the manufacturer or other pool products supplier would have packaged it for sale - even if only to the upscale market. Another place to check would be suppliers who cater to large institutional pools where regulations require constant monitoring. They would most likely have the money and incentive. If it were up to me I'd be calling health departments of large metro area to talk with pool inspectors to see what they see out there.

It sounds like the sensor is what you need. If no sensor is available then you have to invent it. An alternative might be to determine what you can measure and how the given measures might correlate with chlorine levels. As you say, you are willing to give up some accuracy. Tracking various parameters and processing that data might yeild a good surrogate measure - at least good enough to give you an early warning.

Good luck.

 

[TillEulenspiegel]

There are electrical sensors specifically designed to check everything from saline to Co2 to CS gas. start here: **broken link removed**

 

[Richandmaria]

Swimming pool chlorine measurement

Thanks for your responses.

After reading my help request, I think I should have asked anyone? if they have ever experimented with trying to meausre levels of chlorine. I really don't want a commercially made product as this sensor would make this personal project to expensive. I guess I will have to try and measure differnet levels of chlorine by starting with drinking water and then adding small amount of chlorine. Then I will have to compare this to the level of chlorine that I want to be present in my pool. As I said the trick here is what metal elements react mostly with chlorine, then I could measure the voltage and make a scale. As I said it seems to be chemistry as I don't want to measure algae or dirty water and I feel these will cause improper results if the measurng element is affected by them.

I,m just trying to speed up my project, and was wondering if anyone has done any tests.

I'm not sure if if I should re-post the question in this manner, but if anyone reads this please answer.. I'll keep checking..

Thanks
Rich.

 

[Nigel Goodwin]

Re: Swimming pool chlorine measurement

I,m just trying to speed up my project, and was wondering if anyone has done any tests.

I'm not sure if if I should re-post the question in this manner, but if anyone reads this please answer.. I'll keep checking..

I don't really see as your question is very relevent in an electronics forum, if you wanted to know how to display the output from a sensor - fair enough. But that's not what you're asking, you want to know how to design the sensor itself, which isn't really an electronic problem at all.

As already suggested, try looking for commercial sensors, as least to prove to yourself it can be done - your ideas of adding chlorine to pure water didn't suggest at all how you were considering measuring it?, I suspect you probably don't have an idea which may be workable?.

Although you may be able to measure the level of chlorine in pure water by fairly simple means, it's probably not measuring the chlorine at all - just the level of impurites, so would be useless for your pool application.

 

[Richandmaria]

Swimming pool chlorine..

Nigel .. thanks

You wrote:

I don't really see as your question is very relevant in an electronics forum, if you wanted to know how to display the output from a sensor - fair enough.

You are right. I always look at problems with an electronic view, if I got an answer, I would have no problem writing the code to look at the data or understanding the circuit. I was just hoping someone out their had done something like this, but it looks like no one has even used a sensor and tied to a a processor to measure the chlorine amount. I was hoping someone has tried something.

Thus I agree with you about the relevancy in an electronic form. Maybe the mods can close this and delete it

I will continue searching the net, but I will try universities and chemistry forms.

Thanks to all.

Rich

**broken link removed**