Question about the small tube in the Taylor 2006c

[zonkakiick]

I've bought this kit and, so far, all it seems to be used for is the CYA test (with the black dot at the bottom). The book references the meniscus, curvature, etc... I have no idea what any of this means. All the other tests (ph, alkalinity, chlorine, etc...) use the bigger tube. Does that little one with the curvature matter to these tests? What test is it used for?
I may be missing something obvious, but I'm not understanding the instruction book.
Thanks for any help/insight you might have.

Drew

 

[ajw22]

I've bought this kit and, so far, all it seems to be used for is the CYA test (with the black dot at the bottom). The book references the meniscus, curvature, etc... I have no idea what any of this means. All the other tests (ph, alkalinity, chlorine, etc...) use the bigger tube. Does that little one with the curvature matter to these tests?

The tube with the black dot on the bottom is only used for the CYA test.

Since you look directly down into the tube to view the black dot the meniscus and curvature do not apply.

What test is it used for?

CYA

Know the Right Way to Read a Meniscus

The meniscus is the curve seen at the top of a liquid in response to its container. Here's how to read a meniscus in chemistry.

www.thoughtco.com

 

[zonkakiick]

The tube with the black dot on the bottom is only used for the CYA test.

Since you look directly down into the tube to view the black dot the meniscus and curvature do not apply.



CYA

Know the Right Way to Read a Meniscus

The meniscus is the curve seen at the top of a liquid in response to its container. Here's how to read a meniscus in chemistry.

www.thoughtco.com

Thanks for the quick reply. That is what I was assuming, which leave the obvious question - what is that meniscus/curvature for?
Thanks, again

 

[ajw22]

That is what I was assuming, which leave the obvious question - what is that meniscus/curvature for?

For?

It is a natural effect of putting a liquid in a round tube and viewing it from the side.

Use the low point of the curvature to determine the amount of liquid.

 

[zonkakiick]

I'm really sorry....I'm not getting it. I don't see any curvature in the big tube. It looks pretty flat. When I grab my sample both tubes fill, then I pour some out to get to the 25ml level in the big tube. I look at it at eye level and don't see any curvature in the big tube.
I'm thinking I must be missing something really basic here....
Thanks for your patience with me.

 

[ajw22]

If you don't see it then don't worry about it.

It is not a big deal.

 

[zonkakiick]

Ok....I might be getting it. The larger the tube, obviously, the less the meniscus. So that larger tube has one, but it is fairly small and I'm not noticing it. Does that sound right?
If so, I won't bug you anymore Thanks for you help with this.
Drew

 

[ajw22]

Ok....I might be getting it. The larger the tube, obviously, the less the meniscus. So that larger tube has one, but it is fairly small and I'm not noticing it. Does that sound right?

Works for me if it works for you.

 

[Dirk]

The meniscus is there in the larger vial, just less obvious. You've figured out that the effect is inversely proportional to the diameter of the vial.

You might try different light sources behind or above the vial to better see it.

The meniscus in the CYA test does come into play. Not when viewing from above, but when you view from the side to read the CYA value.

Using consistent testing methods is important, but you're not making rocket fuel. Most of the tests have a ±10% accuracy, so don't make yourself crazy. Pick an MO that works for you, and try to do it the exact same way each time.