When we suspected that the molecular sieve needs replacement, there is a simple test

if you don't know that your sample of molecular sieve is good or bad, there is a sample test that you can do to know that:

first, you should look at it. If there is a dust, large percentage of broken pellets or changing in color, the sample should be replace.

After that (if don't) you can:

Activation:

we can activate molecular sieve by putting it in an oven at (300)°C for two hours. After that place the molecular sieve in room temperature and allow it to cool down over night in dried and clean chamber packed with nitrogen or argon.