a very wise Idea, because if
your "bottle" with the blue crystals is not very new filled up, you will easily see some fine white powder on the rough edges, indicating that your CuSO4
has lost some crystal-water!!So, the only Solution left:
Dry it, till all is white powder, AND keep it ALL TIME in the Exicator AND
under Vacuum! -- Not very nice, at all!The better solution:
Buy a "certified Glass-filter", it's less cost as the procedure above over
a small number of months!! Advantages:
- "You" are stable all the time, - with warranty!
- You are, nearly
- If You buy a Holmium Oxide Filter, You have at the same time an
ABSOLUTE STANDARD for Wavelength-Calibration, too!
Of cource also other Glass-Filters will do!
A good source (Quality!): HELLMA