Anybody use a photometer to measure CYA?

[Major_in_MS]

I was just wondering if anybody here has used a photometer such as this one

http://hannainst.com/products/portable-photometers/hi96722-cyanuric-acid-portable-photometer.html

to measure their CYA levels. If so, what was your impression of the meter/testing?

As subjective as the current methods for CYA measurement is with different people perceiving the black dot differently with varying light and visual abilities I'm wondering if something like this is worthwhile.

 

[YippeeSkippy]

We generally frown on meters to test chemicals with as they're only as good as the calibration, which needs to be performed properly each time its calibrated. And the price! Oy!

I personally think it is easier to get the small sample bottle of CYA Test Reagent that has a known value and learn to read that then move on to your own pool water. Less than $10 for the test reagent, I think?TFTestkits.net

 

[Patrick_B]

Good photometers are excellent but quality instruments cost a good deal more than residential pool owners want to spend. For some tests, they aren't all that practical, such as Calcium hardness

 

[AUSpool]

At $220 it's kind of expensive for one test, probably better quality than a ColourQ but the ColourQ will do all the tests at arround the same price and inherent potential for error. At some point the light source will fade and the curettes will age which will affect the results without the user knowing.

I personally think it is easier to get the small sample bottle of CYA Test Reagent that has a known value and learn to read that then move on to your own pool water. Less than $10 for the test reagent, I think?TFTestkits.net

I agree, a CYA standard solution is the term I think you were after. I have a 50ppm solution, and think it is a must for anyone new to this test. Once it's mixed 50/50 with the detection reagent, R-0013, and shaken for 30 seconds it can be used over and over to get the hang of the test.

 

[Major_in_MS]

Accuracy @ 25°C (77°F)	±1 mg/L ±15% of reading

How would the accuracy/margin of error on this meter translate to ppm?

And yes, at $220 it is rather pricey.

I'll probably just order the 50ppm standard solution (or make some myself.) But then again, my wife tells me all the time that I love to spend money on my "Man Toys." eg. welding machine, wine/beer making equipment, beehives, etc.

 

[AUSpool]

The range and resolution are good. I read the accuracy as +/-1ppm +/-15%, so ar 60ppm that would be +/-10ppm and at 30ppm it would be +/-5.5ppm. So with a reading of 60ppm the actual concentration could be from 50 - 70ppm. If I'm right that's a bit poor but it's probably the nature of the test.


A teacher and pedeatric RN, :bowdown: , my wife of 20 years has a pHD in children's literature and lectures in the same, it's more than a full time job.

 

[Major_in_MS]

The range and resolution are good. I read the accuracy as +/-1ppm +/-15%, so ar 60ppm that would be +/-10ppm and at 30ppm it would be +/-5.5ppm. So with a reading of 60ppm the actual concentration could be from 50 - 70ppm. If I'm right that's a bit poor but it's probably the nature of the test.


A teacher and pedeatric RN, :bowdown: , my wife of 20 years has a pHD in children's literature and lectures in the same, it's more than a full time job.

Thanks for the clarification on the accuracy. I think my eyes and the black dot have about that same margin of error, so I will stop looking for a better way to test CYA.

Sherri, my wife, is so stressed about the rapidly approaching school year. Two and a half more weeks of life by the pool and she'll be back in the classroom.

 

[rolo13]

I was just wondering if anybody here has used a photometer such as this one

http://hannainst.com/products/portable-photometers/hi96722-cyanuric-acid-portable-photometer.html

to measure their CYA levels. If so, what was your impression of the meter/testing?

As subjective as the current methods for CYA measurement is with different people perceiving the black dot differently with varying light and visual abilities I'm wondering if something like this is worthwhile.

I have started using LaMotte Colour Q test kit for the pools I look after, and so far it seems to be working very well. Like any kit you have to look after it and use properley, if you do then it will work for you. Yes they are expensive compared to strips, but get cheaper after initial purchase, the Colour Q does all the test I need, not just CYA, for less money than the product you stated. Keep the test tubes clean & change every season ( I got a set with the reagants kit I bought) But like most things in life what works for me may not suit you, happy pooling!!

 

[tfoggo]

I use this photometer (actually a slightly earlier version of it) and love it. It measures CYA as well as all other tests you're likely to need. It's expensive though and requires annual re-calibration by the manufacturer (which also costs). Bought it in a moment of weakness but haven't regretted it - I've used it pretty much daily for 4 years.

 

[del]

I bought a turbidity meter on Ebay for a few dollars. I looked up on another post the correlation between NTU units and CYA. I also made up calibrated solutions and found the CYA to be very accurate based on the NTU measurement. It was much more accurate and repeatable than the drops. I am not too sure how the photometer works, but I suspect that it is similar to my turbidity meter. I hope this helps at least a bit.

 

[max2k]

I bought a turbidity meter on Ebay for a few dollars. I looked up on another post the correlation between NTU units and CYA. I also made up calibrated solutions and found the CYA to be very accurate based on the NTU measurement. It was much more accurate and repeatable than the drops. I am not too sure how the photometer works, but I suspect that it is similar to my turbidity meter. I hope this helps at least a bit.

how much were few dollars? Could you provide more details?

 

[Griswald]

how much were few dollars? Could you provide more details?

Any one I can find is nearly $2000.

That's a lot of 50ppm sample bottles worth.

 

[del]

I think that I paid under $20 for it on Ebay. I had to replace a light bulb and I had to buy a new test tube. Still, I doubt I had much over $50 in it. Again, it works just great.

 

[max2k]

I think that I paid under $20 for it on Ebay. I had to replace a light bulb and I had to buy a new test tube. Still, I doubt I had much over $50 in it. Again, it works just great.

have you got a chance to calibrate it? Like buying known concentration solution(s) and see what it shows? When some meter shows some numbers they're just that- some numbers unless it comes with very solid spec and produces consistent results on standard solutions. That usually comes with matching price tag, that's why I'm asking so many 'validation' questions in case you came across more affordable unit. +- 5% in 30-100 ppm range would be quite useable. If the manufacturer is serious and understands relation between accuracy and resolution such device wouldn't be showing ridiculous values like 33.5 ppm . 30-35-40... is all we need, 2 digit indicator would be quite enough.