How can I ensure an accurate Hanna reading?

[jayteerq]

I’m stressed!!! lol having trust issues. Recently switched over to ABC reagent for my Trident. It’s been a week so I wanted to double check readings against the Hanna checker. My current Alk reading on Trident is 9.59. My first Hanna reading was 10.58. I thought it was insanely far off so I tried again. Second reading was 10.13. I thought ah what the heck let’s try a third. Third reading was 9.63. The process for all 3 checks was the same! Could something be wrong with my Hanna Checker?? Should I reach out to Hanna? The checker is less than 6 months old. Reagent is far from expiration

 

[gbroadbridge]

Why are there 3 cuvettes in the photo?

You should be using just one.

 

[KrisReef]

I can see from here that the vials were filled to different levels each sample.

I use and recommend using a 10ml syringe to fill the cuvettes to the same ml each time. I have found that it helps improve repeatability of testing.

I also triple rinse and store the cuvettes with RODI water after testing. It prevents cross contamination and helps keep the glass clean for long life and testing vitality.

Most of these tips I learned from other folks on here. The other solid is to insure the cuvette goes into the tester the same way/place each time. I use the paint marks on the cuvette to line up with the top edge of the tester, and use the counters for other tests to ensure the time for each test is the same. The time is more important for P, and for dKH I try to shake invert the vial the same amount and wait ~15 seconds before pressing the button.

Using them the same way helps reduce testing process errors and helps provide results that indicate if the parameters are stable or not.

GL.

 

[jayteerq]

Why are there 3 cuvettes in the photo?

You should be using just one.

???? Huh???? lol I did the test 4 different times

 

[jayteerq]

I can see from here that the vials were filled to different levels each sample.

I use and recommend using a 10ml syringe to fill the cuvettes to the same ml each time. I have found that it helps improve repeatability of testing.

I also triple rinse and store the cuvettes with RODI water after testing. It prevents cross contamination and helps keep the glass clean for long life and testing vitality.

Most of these tips I learned from other folks on here. The other solid is to insure the cuvette goes into the tester the same way/place each time. I use the paint marks on the cuvette to line up with the top edge of the tester, and use the counters for other tests to ensure the time for each test is the same. The time is more important for P, and for dKH I try to shake invert the vial the same amount and wait ~15 seconds before pressing the button.

Using them the same way helps reduce testing process errors and helps provide results that indicate if the parameters are stable or not.

GL.

Wow! Nuts. I recently found out the 10mL line on the cuvette isn’t even 10mL so I started to pump 2 5mL parts. I try my best to be consistent but man I didn’t know the readings can be altered that easily!

 

[gbroadbridge]

???? Huh???? lol I did the test 4 different times

But if you're using different cuvettes you have introduced a measurement variation.
It is not the same test 3 times

These devices are very sensitive.

 

[jayteerq]

But if you're using different cuvettes you have introduced a measurement variation.
It is not the same test 3 times

These devices are very sensitive.l

Wow my apologies that’s insane I didn’t know it mattered that much. I carefully rinse out after every test so assumed each cuvette is good as new

 

[gbroadbridge]

Wow my apologies that’s insane I didn’t know it mattered that much. I carefully rinse out after every test so assumed each cuvette is good as new

It can make a difference.

Also keep in mind, the stated measurement accuracy of the instrument is +- 0.3dKh (5ppm) so the results you saw are quite possibly *all* correct.

 

[jayteerq]

It can make a difference.

Also keep in mind, the stated measurement accuracy of the instrument is +- 0.3dKh (5ppm) so the results you saw are quite possibly *all* correct.

I also have this problem of always wanting things to be perfect so I’m always chasing numbers lol. Trying to Cut that mentality off

 

[chip shop]

Also refrigerate the regant

 

[VintageReefer]

The lines aren’t accurate on the vial. You need to consistently pull 10ml of sample water exactly the same each time. It’s very hard to do by eye

I bought this and it’s made things so much easier. Set the dial for 10ml, push the plunger, it will extract 10ml exactly the same each time.

Amazon.com

 

[VintageReefer]

I also have this problem of always wanting things to be perfect so I’m always chasing numbers lol. Trying to Cut that mentality off

Pick one testing device to trust or accept that (hypothetically) one typically reads 9 while the other reads 10.

Consistency and stability is more important

And use the same glass vial. If you test 2 or 3 times in a row, use the same vial. And use the white printing to align in the egg tester in the same orientation each time

And consider the pipette I posted. It will give you the same amount of water each time

 

[rockdiver]

I dont understand how you put in vial. Why would it make a differance?
I do all the other stuff, will look at the pipette measurement item that looked nice

 

[Bruttall]

I have seen Salifert, Hanna and API all give the same water different readings. Rather than chase accuracy I use the same test every time, if my Hanna CA is off 30pts, then in every test I do it is off 30pts and I can see if my levels are changing.

Use the ICP tests to determine how OFF your test is and then compensate mathematically when you test by using your tests on the same water batch as you send to ICP that day.

Does it really matter if Salifert says you have 10.5dkh while Hanna says you have 9.75dkh? as long as you use the same test every time you will see when the changes occur.

 

[taricha]

The trident and the hanna checker use different methods.
the hanna alk accuracy statement is +-5ppm +-5%.

all those posted values from trident and hanna: 9.59, 10.58, 10.13, 9.63.
All those values are 10.1+-5%.

This is very good agreement between two different devices that aren't even measuring alk the same way!

 

[jayteerq]

Also refrigerate the regant

Seriously??????

 

[VintageReefer]

Seriously??????

Yes. Been proven to prolong life and accuracy

 

[chip shop]

Seriously??????

Yes

 

[jayteerq]

Yes. Been proven to prolong life and accuracy

holy cow I’ll do that now lol

 

[scotty333]

As said, you fill with 10ml water not fill the bottle like it shows on your pic

I was having differences with the phosphate ulr against the lr, the lr always measures half the ulr so if both are the same readings each time your good

My procedure is like this , use the pipette to fill to the line in the middle of the cuvette , the edges are higher but that’s what your looking for or buy the 10ml pipette as suggested above but for me I’m happy filing the cuvette tp the same mark on the glass . This is what Hanna say you should do
It doesn’t matter if it’s 9.9ml but consistency is key.
After filing , dry with a soft napkin or lint free cloth , don’t run to hard cos the lines come off! So annoying

Pug in the tester with the 10ml mark facing you and c1 with lid closed of course

Take out the vial and use a ear bud ( Q tip to you guys) and dry the top and inside above the water line , inset the” Hanna no spill “ and pour in the regent , tap the sachet to get all the powder out
Close lid , shake for 1 n half minutes and let it settle 20 seconds
Invert the bottle a few times slowly so no bubbles are on the sides
Insert and c2