About this Hanna ppm gauge...

I'm not a noob per se, just with this meter. I've never used one of these, the instructions say the probe is supposed to be stored in some sort of fluid, but when my boss handed it to me and said i could use it, it was not stored so. No cap, either. Or calibration solutions.

How badly is this thing fucked up? The lady at the grow store says I need a new probe (and guess who's selling?), But do I really? Can I restore it by re-storing it?
For the record, it seems to work, though it's accuracy is probably in question.

They all shit eventually.
Buy a handful of cheap meters, you can compare them to each other when in doubt.

I'm an outdoor guy. Typically, I don't get "runoff" to test, i slurry test, so pH reagent drops have sufficed for me for awhile now.
But the tool is available, I may as well learn it. Compared to the drops, they're in the same ballpark for checking pH, and I got some calibration fluid, I just wanted to know if it's really all that important.
I imagine the storage fluid's purpose is to keep minerals from building up on the probe sensors, right?