Sorry but
@strangelife's answer is wrong, that's not how this test kit works.
This kit measures
PPM (parts per million). I will spare you the math but
1ppm = 1mg/L. This kit measures
up to 1ppm (which is much, much lower if compared to other test kits who go up to 5 or 10). If you want to use your kit, you have to create a solution with a concentration of SN of maximum
1mg/L.
Here's how to:
- Put 1g of SN in a 1 liter water container, stir/shake carefully
- Measure 1ml out of that solution - this equals 1mg of SN - and add it to another 1 liter water container, stir/shake carefully
- Now you have a 1mg/L solution. If you test it and get close to 1,0 then your SN is pure
I know it may upset you but that's the way this kit works. It should be pretty reliable, but if you're not comfortable with it you may want to try another one.
I was thinking of buying the same kit myself but now I'm not quite sure. By the way, you're not supposed to look at the results like you seem to be doing - the kit includes two vials for a reason, take a look at this
video