How to test N?

[ddd1234]

People say that they test their N... but how? Do they send it to the lab or something?

 

[canna2]

Just taste / drink a very tiny amount. If you fall asleep, it's N.

I think that's what people refer to mostly but there's also sticks you can use and test for barbiturates.

Sticks are not 100% accurate since they only show you if it's traces of barbiturates and not how many % of the solution is.

 

[ddd1234]

how to check % ?