Hanna ULR Issues

[jtl]

I am getting inconsistent readings. I checked my PO4 four times and got 0.135, 0.202, 0.0, and 0.0. I am usually 0.04 or less. I have not changed anything so I wonder what is going on?

 

[Dan_P]

I am getting inconsistent readings. I checked my PO4 four times and got 0.135, 0.202, 0.0, and 0.0. I am usually 0.04 or less. I have not changed anything so I wonder what is going on?

If you have a second Hanna test vial, fill it with RODI or tank water. It will serve as the blank, or the vial you put into the Checker when “C1” flashes. Prepare a test sample with the usual mixing and hold times. The idea is to to retest the same sample over and over again, using the blank for “C1” and the same test sample for “C2”. If the Checker is the problem, instead of getting very similar readings each time, they might bounce around.

If the Checker behaves consistently, then the variation is coming from bad reagents, possible, not likely or a contaminated or dirty vial, which is more likely.

 

[jtl]

If you have a second Hanna test vial, fill it with RODI or tank water. It will serve as the blank, or the vial you put into the Checker when “C1” flashes. Prepare a test sample with the usual mixing and hold times. The idea is to to retest the same sample over and over again, using the blank for “C1” and the same test sample for “C2”. If the Checker is the problem, instead of getting very similar readings each time, they might bounce around.

If the Checker behaves consistently, then the variation is coming from bad reagents, possible, not likely or a contaminated or dirty vial, which is more likely.

I will try that. I clean my vial after use and even tried the second vial. I also place the vials in the test in the same position so the tester reads from the same loacation.

 

[BeejReef]

I had the same issue. Was advised to use the same vial to zero the meter and to do the actual test. Add C1, get it out quick, add reagent, shake, polish, put it back in for add C2. Mine is the LR, not the ULR. I'm no expert, but that was the overwhelming consensus when I tried the #askBRSTV fb page. I think it was even a hanna rep. Point being, it's a PAIN cuz mine times out after 3 mins and getting the regents out of that little envelope and shaking for two minutes, plus buffing the vial is hard. Even so, my results have been a lot more consistent since using that approach. Still not what I'd like, but I'm not questioning the trends anyhow.

 

[jtl]

I had the same issue. Was advised to use the same vial to zero the meter and to do the actual test. Add C1, get it out quick, add reagent, shake, polish, put it back in for add C2. Mine is the LR, not the ULR. I'm no expert, but that was the overwhelming consensus when I tried the #askBRSTV fb page. I think it was even a hanna rep. Point being, it's a PAIN cuz mine times out after 3 mins and getting the regents out of that little envelope and shaking for two minutes, plus buffing the vial is hard. Even so, my results have been a lot more consistent since using that approach. Still not what I'd like, but I'm not questioning the trends anyhow.

I have always used the same vial to zero the meter and test. I get the regents set to go and shake the vial until there is no residue. Has always worked until today.

 

[BeejReef]

I have always used the same vial to zero the meter and test. I get the regents set to go and shake the vial until there is no residue. Has always worked until today.

I don't know why
It's frustrating, especially w the digital illusion of total precision. Testing a lot in a row like that, maybe you got a drop of water inside the checker? I soaked both my vials in distilled vinegar and polished them w RODI to make me feel better. Not sure it made any difference.

https://blog.hannainst.com/checker-best-practices

maybe your vials have finally stained a little? They sell replacements cheap.

 

[pelphrey]

I use the same vial. I cut it open and get it ready, do my first test add reagents shake for one minute. Insert into the checker, press and hold the button to start the 3 minute timer. Once that is started I pull out the vial and shake for another minute. Re-enter with 2 minutes left and wait to get my reading.

 

[jsker]

I use two cuvetts, that I clean in the dishwasher and rinse with distilled water before I test. One for the test sample filled with tank water and the blank filled with tank water to solve the time out issue. I use a magnetic stirrer to stir the test sample for two minutes. I wipe down the blank with a clean napkin and place the blank in the Hanna unit while the sample is stirring. Once the same has it 2 minute stir, then I place the sample in the unit and press for the 3 minute timer on the unit to start. I wait and get my results.

Make sure the cuvetts are clean and the same is shaken/stirred for the 2 minutes.

 

[jtl]

I use two cuvetts, that I clean in the dishwasher and rinse with distilled water before I test. One for the test sample filled with tank water and the blank filled with tank water to solve the time out issue. I use a magnetic stirrer to stir the test sample for two minutes. I wipe down the blank with a clean napkin and place the blank in the Hanna unit while the sample is stirring. Once the same has it 2 minute stir, then I place the sample in the unit and press for the 3 minute timer on the unit to start. I wait and get my results.

Make sure the cuvetts are clean and the same is shaken/stirred for the 2 minutes.

I would be concerned that the dishwasher leaves a lasting PO4 residue given the wash and drying cycle. I don't think the 2 minute shake time is critical, the reagent just need to be totally dissolved. I have been doing this weekly, same procedure, for over a year and this is the first problem. The previous tests have been as expected.

 

[Salt1972]

I don't think Dan P was recommending the use of 2 cuvettes ongoing. Hanna says to use a single. Dan's method using 2 cuvettes would indicate whether the issue was with the tester or the reagents. i.e. If the tester gives the same readings (within error) on the same samples, then the tester is good and either the reagents or the prep is bad.

If you have a second Hanna test vial, fill it with RODI or tank water. It will serve as the blank, or the vial you put into the Checker when “C1” flashes. Prepare a test sample with the usual mixing and hold times. The idea is to to retest the same sample over and over again, using the blank for “C1” and the same test sample for “C2”. If the Checker is the problem, instead of getting very similar readings each time, they might bounce around.

If the Checker behaves consistently, then the variation is coming from bad reagents, possible, not likely or a contaminated or dirty vial, which is more likely.

 

[sghera64]

Hey everyone. You must have the Checker analyze the sample exactly 5 minutes after the powdered reagent is added and mixing begins. Once that 5 minute mark passes, the color fades. So, for about 5 minutes the color develops and after 5 minutes it fades (I.e. lambda-max is at 5 minutes).

For repeatability and reproducibility, mix for exactly 2 minutes (time it with phone stop watch) and start the checker’s 3 minute on-board timer right at the 2 minute mark.

The above was obtained by @MnFish1 directly from Hanna.

 

[Makers Marc]

I have to ask. How long have you had yours? I was hitting my 3 yr mark and it just started messing up, then flashing high light or too low light.

The green led was still blinking with the cap open. Hanna said the bulb starts going out over time.

 

[LilElroyJetson]

Sounds like you know how to use it correctly. If you've had it long enough, maybe something caused the colorimeter sensor to go bad. First thing I might try is swapping out the battery, if the issue persists, I'd contact Hanna, they have great customer service.

 

[Dan_P]

Hey everyone. You must have the Checker analyze the sample exactly 5 minutes after the powdered reagent is added and mixing begins. Once that 5 minute mark passes, the color fades. So, for about 5 minutes the color develops and after 5 minutes it fades (I.e. lambda-max is at 5 minutes).

For repeatability and reproducibility, mix for exactly 2 minutes (time it with phone stop watch) and start the checker’s 3 minute on-board timer right at the 2 minute mark.

The above was obtained by @MnFish1 directly from Hanna.

A little perspective is needed here.

How much does color fade? 1%? 5%? Hanna is being conservative here when they describe the color evolution. That is very good. They simply cannot support modifications to their procedures or equipment, but in fact their is leeway.

Unless you are doing scientific research, you do not need a stop watch or start obsessing about timing events to the second to obtain good results. For us, consistency in running the test is far more important than developing the test color for 5.0 minutes.

 

[Thor2j]

I use two cuvetts, that I clean in the dishwasher and rinse with distilled water before I test. One for the test sample filled with tank water and the blank filled with tank water to solve the time out issue. I use a magnetic stirrer to stir the test sample for two minutes. I wipe down the blank with a clean napkin and place the blank in the Hanna unit while the sample is stirring. Once the same has it 2 minute stir, then I place the sample in the unit and press for the 3 minute timer on the unit to start. I wait and get my results.

Make sure the cuvetts are clean and the same is shaken/stirred for the 2 minutes.

How to u get magnetic stirrer out of vial??

I'm thinking of using one.

 

[Jason mack]

I have always used 2 curvetts ..with my hanna ..never had issues

 

[jsker]

How to u get magnetic stirrer out of vial??

I'm thinking of using one.

A stirr bar retriever make life so much easier link I use the 5x5mm stirr bars.

 

[jsker]

FYI, speaking with Kevin Costa at RAP, Hanna is re timing the new ULR and reagent for 7 minutes instead of 5.

leaves a lasting PO4 residue

Hence the rinse with distilled water. I have not had an issue, Glass will not saturate.

 

[Makers Marc]

FYI, speaking with Kevin Costa at RAP, Hanna is re timing the new ULR and reagent for 7 minutes instead of 5.



Hence the rinse with distilled water. I have not had an issue, Glass will not saturate.

So I just bought a replacement ULR, does that mean I should now shake for 2 and sit for 5 mins?

 

[jsker]

So I just bought a replacement ULR, does that mean I should now shake for 2 and sit for 5 mins?

The was I understand, is the reagents take longer to react and the shake time is the same. Check the units time to make sure that the unit timer is 3 or five minutes and the will be the clue to the timing