Hanna cuvettes are off!!

[Corgigirl]

you mean like the same small amount of error as a label placed 0.5mm off? ;)
Yea...

I would venture to say it’s a smaller margin of error than that, but yes :). If you want more accuracy, you can use the 1ml syringes, less margin of error but that would be tedious .....lol.

 

[SMSREEF]

Let’s break this down:

I just don’t like people who are entitled and need to have everything on a silver platter handed to them.

No silver platter comes with the Hanna tester, and it is certainly is not handed to us. We buy them. They come with a 10ml vial with a 10ml line.
The new vials they are producing, that also do not come with said silver platter, nor are they handed to us, also have said 10ml line.
Expectation is that the line is reliably 10ml.

If they can’t even put the lines on all the vials correctly what makes you think the lines on the syringe that came with it are correct? How do you those aren’t off either?

They may be, but the same syringe was used to fill the vials.
And If you are in the hospital and supposed to get TPA for your acute ischemic stroke or heart attack, you better hope the syringes are correct.

 

[Corgigirl]

If I were Hanna, I would have left the markings off and gone with the syringe, but then we would have less to ***** about ;)

 

[92Miata]

Yes this is well known, and it also annoys me as you are paying top dollar for a precise piece of “measuring “ equipment and and their very own vials are out of spec. Do you work for Hanna and service their screen printing machine? ;Happy

He's made a bunch of posts like this lately berating people for making legitimate complaints about crappy products.


Not sure what he's trying to achieve.

 

[SMSREEF]

He's made a bunch of posts like this lately berating people for making legitimate complaints about crappy products.


Not sure what he's trying to achieve.

I think he is a she, but not 100% sure. I think we all just think it’s a guy because it’s usually guys who do this

 

[K7BMG]

The reality is there will not be a significant differance in the test.
What know one here has done to prove this is an issue at all is test with both to the perspective lines and compair the result.
I have often double tested with the same vial when I feel somethings wrong. 90% of the time I get the same result, 10% I get a result thats off by .1 this is no big deal.
So I recomend to do two tests per vial at the labeled mark and post the result. Lets see if it makes any differance at all.
Then how significant or relevant is that result.
I will get the complaint if vial 1 were to read a Alk of 7 and vial 2 8.
However I doubt this will be the case.

So lets do a control.
Put a sharpie single marker dot on the original vile above the line to not interfere wkth the test then Two dots on the new vial.
Then run two tests on each vial and take a pic of the numbers the checkers.
This will prove if there is an issue to be concerned over or not.

Then we should do the same test with several syringes.
Fill each with 10ml of water dispense into a single vial, make a mark.
Compleatly dry the vial and test the next syringe. Lets see how accurate thay are.

 

[FlyPenFly]

Whatever you do, just do it consistently. Also just use a syringe because then you'll at least be consistent between cuvettes.

 

[X-37B]

The reality is there will not be a significant differance in the test.
What know one here has done to prove this is an issue at all is test with both to the perspective lines and compair the result.
I have often double tested with the same vial when I feel somethings wrong. 90% of the time I get the same result, 10% I get a result thats off by .1 this is no big deal.
So I recomend to do two tests per vial at the labeled mark and post the result. Lets see if it makes any differance at all.
Then how significant or relevant is that result.
I will get the complaint if vial 1 were to read a Alk of 7 and vial 2 8.
However I doubt this will be the case.

So lets do a control.
Put a sharpie single marker dot on the original vile above the line to not interfere wkth the test then Two dots on the new vial.
Then run two tests on each vial and take a pic of the numbers the checkers.
This will prove if there is an issue to be concerned over or not.

Then we should do the same test with several syringes.
Fill each with 10ml of water dispense into a single vial, make a mark.
Compleatly dry the vial and test the next syringe. Lets see how accurate thay are.

Just did a quick morning test for alk.
Filled to the line:
Alk 135-7.56
Filled to the line and add .5 ml.
Alk 132-7.39.
A difference of .17.
I can live with either of those numbers.
Im not going to worry about the line as long as the test is the same every time.

 

[FlyPenFly]

Also keep in mind, the state of your battery, optical differences between cuvettes, the temperature of the sample, if Venus is in retrograde might affect your tests as well and it's not meant to be exactly the same.

I do highly recommend getting the calibration sample from Hanna though to make sure your device is working within parameters. That's probably the more important you can do. I always check the calibration when I get a wild result that doesn't seem right.

 

[92Miata]

@90's reefer

If you've got multiple cuvettes, the results aren't going to be the same every time, though.


I'm regularly adjusting alk dosing on changes in the .2 range.

 

[K7BMG]

Just did a quick morning test for alk.
Filled to the line:
Alk 135-7.56
Filled to the line and add .5 ml.
Alk 132-7.39.
A difference of .17.
Im not going to worry about the line as long as the test is the same every time.

Exactly

 

[92Miata]

Also keep in mind, the state of your battery, optical differences between cuvettes, the temperature of the sample, if Venus is in retrograde might affect your tests as well and it's not meant to be exactly the same.

I do highly recommend getting the calibration sample from Hanna though to make sure your device is working within parameters. That's probably the more important you can do. I always check the calibration when I get a wild result that doesn't seem right.

The problem with the calibration sample is that it's 5 dKH, and it's only made to a +/- .2 accuracy.

IE, it's easy to have a meter that reads 'fine' with the sample and still be significantly off when testing.

 

[K7BMG]

@90's reefer

If you've got multiple cuvettes, the results aren't going to be the same every time, though.


I'm regularly adjusting alk dosing on changes in the .2 range.

Thats fine, but the same cuvettes should always be used for the same test. Repeatedly.
Especially if you intend to make adjustmens on fractions that low.

 

[FlyPenFly]

The sample is really just another data point to check the equipment. Things can of course always be off no matter what but I'd rather at least have the sample than not.

Also, unless the sticks are horribly sick .2 variations in alkalinity will be meaningless and just happen naturally anyway no matter how you dose.

 

[SMSREEF]

Also keep in mind, the state of your battery, optical differences between cuvettes, the temperature of the sample, if Venus is in retrograde might affect your tests as well and it's not meant to be exactly the same.

I do highly recommend getting the calibration sample from Hanna though to make sure your device is working within parameters. That's probably the more important you can do. I always check the calibration when I get a wild result that doesn't seem right.

I love the mercury in retrograde part...

I’m gonna order the calibration sample. Thanks for that tip.

 

[X-37B]

The problem with the calibration sample is that it's 5 dKH, and it's only made to a +/- .2 accuracy.

IE, it's easy to have a meter that reads 'fine' with the sample and still be significantly off when testing.

Thats where another means of testing comes in.

 

[92Miata]

The sample is really just another data point to check the equipment. Things can of course always be off no matter what but I'd rather at least have the sample than not.

Also, unless the sticks are horribly sick .2 variations in alkalinity will be meaningless and just happen naturally anyway no matter how you dose.

It's not a useful data point - it's too far from the target range. You're much better off making some of Randy's calibration solution that is 8 dkH. At least that way you know what your accuracy is in the range that matters.

It's a bit like checking your refractometer with RODI. 0 @ 0 doesn't really mean anything when you're trying to hit 1.026.

 

[SMSREEF]

It's not a useful data point - it's too far from the target range. You're much better off making some of Randy's calibration solution that is 8 dkH. At least that way you know what your accuracy is in the range that matters.

It's a bit like checking your refractometer with RODI. 0 @ 0 doesn't really mean anything when you're trying to hit 1.026.

If I remember correctly, Randy was not sure it would work for the Hanna tester. It may need to be saltwater.

Has anyone tried it? This would be preferable for sure.

 

[92Miata]

Thats where another means of testing comes in.

Yes - I use other methods because Hanna's quality control is poor and their reference samples don't actually tell me if my meter is actually accurate - so I have to assume it's inaccurate.

Isn't that kind of the point here?

 

[Dan_P]

I have been using a 10ml syringe to accurately fill my cuvette for awhile with no problem. I recently bought new cuvettes from saltwateraquarium.com they came and they weren't the same as the old ones and fill past the 10ml line. I thought maybe I got some bad cuvettes so I ordered more from marinedepot.com they were the same they fill up past the 10ml line. So im not sure if I'm supposed to fill to the line or use a syringe to accurately fill 10 ml??
Here is a picture of my old cuvette (on the left) and new cuvette (on the right) both filled with the same 10ml syringe with 10ml of water:

Syringes are not very accurate either and susceptible to user error. If you aren’t weighing the water added to the vial, you really don’t know how much you are actually adding via the syringe.