I think mine is an Omega 2 - I will have to check. It does have a user replacable 'nose', but I have not yet needed to swap it out.

It eats the batteries if they are left in it, even if you tell it to turn off and 3-lr44's are a hassle to forever change, so I pull them between uses.

Yes, I store it upright, hanging on a nail on the wall at the end of the shelf, the bottom sensor end poking though some saran wrap stretched over a beaker of the KCL conditioning solution. The saran bit keeps the solution from evaporating very quickly. Ocassionally some r/o is used to bring it back to the marked level after a few idle months.

I rinse it in R/O water prior to use, then calibrate with the buffer solution , then rinse again, then a brief dip in the colour chem etc under measure, then a dip in the r/o again

Then I fish out the temp conversion chart if I am a long way from 20C, to correct the measured pH level. Yes, this is done automatically in fancier units, but I too feared the photochems would kill it fast, so I stayed down market and simple when I bought this, my first unit.

Once I am happy with the measures taken in an active measuring sesion, after tweaking the pH of the solutions under test, and am done for th session, I peel the batteries out and hang it back in it's conditioning solution after the final r/o water rinse.

It gets used 6-7 times a year and when used measures all of the mix from scratch chems for c-41 or e-6. 6 years on it is still ticking.

I bought it from a local hydroponic 'grow op' supply store.
I figured the users there would give enough volume the vendor would have a good price.
I was his first customer to use his new credit card terminal, although he had been running for 3 years when I strolled in.
Mostly a cash business I guess!!!