Help with hanna phosphate checker

[LeJeune981]

I know the instructions are pretty straight forward... but here is where I am encountering an issue... it says to add the reagent.. then shake gently for 2 minutes...
Every time I do this.. the checker turns off and I have to re zero it... therefore I have been using both cuvettes to do a single test.. one to zero..one to test..

There has to be a better way..

Can anyone point me in the right direction?

Thank you

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[mcgyvr]

shake faster

The timeout is supposed to be about 3 minutes (2 minutes after a reading has been completed) so you should be okay with a 2 minute shake of the reagent.

Time how long it takes to shutoff during a reading.. It may be oh "faulty" if its not..
Its not correct to use both vials as there could be a difference in the 2..

 

[erin1224]

Do you have two glass vials? If so, fill one with the water +reagent, and other with tank water and no reagent. Then they're both ready to go. Just mix the reagent one, and use the other to calibrate when you're ready!

 

[Tripod1404]

if you press and hold the button, it turns on a 3 min timer.

After you zero you photometer, take out the vial and put in the reagent. After this hold the button for 1-2 secs until the timer starts, it will count down from 3mins. While it counts down, shake the vial for 2 mins. After shaking is done put it back into the photometer and wait until the timer runs out and it automatically makes the measurement.

 

[Tripod1404]

Do you have two glass vials? If so, fill one with the water +reagent, and other with tank water and no reagent. Then they're both ready to go. Just mix the reagent one, and use the other to calibrate when you're ready!

that is a very bad idea. you never use different vials for blank and sample for a spectrometer.

 

[thegrun]

Older models of the phosphate checker had a 2 minute time limit between functions and it sounds like you must have an older model, the newer models give you three minutes. I agree you do not want to change vials because each vial has a different refraction rate and clarity. I also would not start the three minute count down until after you have completed the shaking, the three minutes is intended to allow any microbubbles to rise in the vial so they do not effect the test result. I would simply shake the vial for 90 seconds, quickly tap the vial to remove any bubbles that stick to the sides of the glass and then place the vial in the checker and start the count down timer before the two minutes expire.

 

[homer1475]

if you press and hold the button, it turns on a 3 min timer.

After you zero you photometer, take out the vial and put in the reagent. After this hold the button for 1-2 secs until the timer starts, it will count down from 3mins. While it counts down, shake the vial for 2 mins. After shaking is done put it back into the photometer and wait until the timer runs out and it automatically makes the measurement.

This +1000

If you read the directions, they tell you do this exact procedure.

0 the meter with plain SW, add reagent, press button to start timer, shake for 2 minutes, place cuvette in meter, wait for the timer to 0 out for the reading.

 

[pisanoal]

This +1000

If you read the directions, they tell you do this exact procedure.

0 the meter with plain SW, add reagent, press button to start timer, shake for 2 minutes, place cuvette in meter, wait for the timer to 0 out for the reading.

Just for clarity, are we talking about the LR phosphate/phosphorous ULR? (same procedure/reagent-different displays).

If so...

It states to allow 3 minutes after mixing, so starting the 3 minute timer right when you add the reagent means you have an underreacted test. Also, only allowing a minute for bubbles to disperse and not inspecting for and removing bubbles clinging to the glass can cause a very inaccurate reading. It actually states just that in the tips section.

The instructions say to zero your sample, remove cuvette, add reagent, shake for 2 minutes, place cuvette back in meter, press and hold the button for the 3 minute timer, wait for timer to run out and reading is displayed.

Before anyone argues against this, I have it open off of Hanna's website and am referencing it as I type this. So please check before you do.

Also, it is fine to use two cuvettes as long as you check them. Add saltwater to both, zero one, read the other. Then test them in reverse order. If they both come out zero, you are good to go. Lab grade spectrophotometer companies also sell matched pairs of cuvettes to be used in this way. They are really expensive, but someone said you should never do this, and that's not strictly true. We do this in our certified waste water lab, and have to for certain lab tests (which are ran using a very specific/accepted standard). If you are concerned about it, do the zero test every once in a while just to make sure. I also insert my vials in the same orientation every time, mL reading in front to reduce variability.

 

[LeJeune981]

Just for clarity, are we talking about the LR phosphate/phosphorous ULR? (same procedure/reagent-different displays).

If so...

It states to allow 3 minutes after mixing, so starting the 3 minute timer right when you add the reagent means you have an underreacted test. Also, only allowing a minute for bubbles to disperse and not inspecting for and removing bubbles clinging to the glass can cause a very inaccurate reading. It actually states just that in the tips section.

The instructions say to zero your sample, remove cuvette, add reagent, shake for 2 minutes, place cuvette back in meter, press and hold the button for the 3 minute timer, wait for timer to run out and reading is displayed.

Before anyone argues against this, I have it open off of Hanna's website and am referencing it as I type this. So please check before you do.

Also, it is fine to use two cuvettes as long as you check them. Add saltwater to both, zero one, read the other. Then test them in reverse order. If they both come out zero, you are good to go. Lab grade spectrophotometer companies also sell matched pairs of cuvettes to be used in this way. They are really expensive, but someone said you should never do this, and that's not strictly true. We do this in our certified waste water lab, and have to for certain lab tests. (which are ran using a very specific/accepted standard). If you are concerned about it, do the zero test every once in a while just to make sure. I also insert my vials in the same orientation every time, mL reading in front to reduce variability.

My instructions match what you say exactly... shake for 2 min.. then hold button for the timer to start

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[LeJeune981]

And yes.. it is the phosphate checker.. not the ultra low ppb checker

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[Optionman]

here's what i do:

before you do anything, cut open the reagent package and pull the sides apart at the top to form a vase shape....softly shake the package to get all the reagent at the bottom...set this aside.

then fill the 10ml vial, do the first step
then take vile and pour reagent in, shake/swirl for 2 minutes
then replace and hold button to start the 3 min countdown


opening and getting the reagent package ready is the key to getting the test done within the given time

good luck

 

[pisanoal]

And yes.. it is the phosphate checker.. not the ultra low ppb checker

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Ok.

If memory serves, the only difference between the two is the LR phosphate checker does the math for you on converting ppb total phosphorous to ppm phosphate. Reagent is the same.

 

[pisanoal]

here's what i do:

before you do anything, cut open the reagent package and pull the sides apart at the top to form a vase shape....softly shake the package to get all the reagent at the bottom...set this aside.

then fill the 10ml vial, do the first step
then take vile and pour reagent in, shake/swirl for 2 minutes
then replace and hold button to start the 3 min countdown


opening and getting the reagent package ready is the key to getting the test done within the given time

good luck

This seems like good advice. Never tried it, but I think I will next time I check phos.

 

[homer1475]

Guess I misunderstood my directions then. I have always done it the way I described.

I guess I had always ASSUMED the timer was for the 2 minute shake/swirl, and 1 minute for it to settle.

 

[Optionman]

Full 3 minutes is definitely AFTER you shake/swirl for 2 minutes. I've made the mistake of not looking at the result after the 3 min countdown and the unit turning off. Very frustrating to have to do test over.


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[Heart of Dixie]

I put salt water into # 1 & 2. Mix the reagent into # 2, shake for 2 minutes, wipe both bottles clean of finger prints, then start the procedure.

 

[thegrun]

I put salt water into # 1 & 2. Mix the reagent into # 2, shake for 2 minutes, wipe both bottles clean of finger prints, then start the procedure.

As stated above, that is not the optimal procedure and the differences in the two vials will effect the test results.

 

[newbie2014]

To OP; it may help if you use another timer.

This is how I do it. I know I have a 3 mins window of inactivity before the reader turns itself off. So once I take the tube out of the reader (after blanking it), I start a timer on my phone. I need to add the reagent, mix, put the tube back in, and press and hold the button before my phone timer hits the 3 mins mark.

So far so good...............

 

[Optionman]

To OP; it may help if you use another timer.

This is how I do it. I know I have a 3 mins window of inactivity before the reader turns itself off. So once I take the tube out of the reader (after blanking it), I start a timer on my phone. I need to add the reagent, mix, put the tube back in, and press and hold the button before my phone timer hits the 3 mins mark.

So far so good...............

I probably wasn't clear. I get everything done in time, I just get distracted and don't read the final result when it's properly displayed. Total user error. Lol


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[newbie2014]

I meant; to the person who started to thread.................