Help helium related questioning

[DamnDahm]

How would one go about figuring out how much helium is ACTUALLY in a tank, I don't want to waste more cash than needed for a method that won't work

obviously reviews aren't helpful since it's just people wanting to fill balloons, only balloon I wanna fill is the plastic one round my head LMFAO

 

[Fadenself00]

i think generally they mention how many liters of air are in the tank. most balloon gas canisters are also not so heavily compressed AFAIK

 

[Gomomon]

Hey, from personal experience, I followed a popular guide online, but I believe now it's outdated, and I had a failed exit bag attempt three years ago. Regular balloon helium tanks now have a vaulve that wont release gas without someone pushing down at all times. Ngl idk if I was just impatient, a dumbass, or didn't read the instructions carefully enough. But it felt impossible to CTB that way, tho i'm not the most tech-savvy engineery person so....props if you are maybe you can make it work.