Got my potassium test kit

[wasp]

Thought the error would be 5%? Quite a bit far as I'm concerned!

But hey, appreciate the help, I'll keep you posted how it goes.

[lduncan]

Can you tell a difference of 5% in the test?

A 5% in this sort of test isn't that significant considering weighing errors, reading errors, reagent quantity errors, printing errors on the slide comparison sheet etc.

I guess you could always make the standard both ways, and see if you can tell the 5% difference.

[wasp]

Dude! Chill! :lol:

You did not make an error. Just the way it was written could have meant either or.

I appreciate the help!

[lduncan]

:-?

Just putting it in perspective. No major.

[wasp]

Ok I've made your calibrating formula Layton, the revised version to give a level of 380.

Using this calibrating solution, the way my eye reads the kit, I get a reading of around 300 when the line completely fades from view. Reading the link from Bychineva to the thread by Alexander G about how to read the kit, I can see he would have come in at an earlier stage and got a higher number. But for me that's pretty hard to judge, I'd rather have it when the line dissapears from view completely.

Anyhow I've solved it. Instead of using the test vial that comes with the kit, I tried a slightly narrower & taller one from a different kit. Perfect! The test strip line faded from view right on 380, as the view is through a slightly higher distance of test mix. Gives the same reading for NSW, so I think I've got it sussed!

So thanks for the help Layton.

Also, I now have enough of this calibrating solution to last several lifetimes, so anybody else wants some let me know. However the NSW I have tested is the same, so that could be used also, it's just good to have it confirmed by a calibrating standard solution.