# Precision Balance (1mg) vs. Analytical Balance (0.1mg)

I'm in the lucky position to building my own home lab and I'm looking to get a nice balance, but I don't want to waste money on something I won't use though.

I'm currently about to start second year chemistry (Organic) and I plan to take at least a few courses beyond this as time allows (I already have my Comp Sci degree and a full time job and I've been in and out of grad school for Mathematics and Computer Science). So this is just a hobby. As far as what I'll be doing I honestly don't know chemistry well enough to say exactly, but I think it'd be fun to synthesize various molecules you come across and see what kind of purity I could get after running the experiment a few times.

I probably won't ever get much past 4th year undergrad or 1st year graduate level knowledge since I can only take one night class at a time.

I understand that analysis and p chem have a decent amount of use for sub-mg level accuracy, but how often do these situations come up in practice?

Should I spend the extra on a 0.1mg balance or just go for a 1mg balance? This decision won't affect future lab purchases much more likely just the timeline of the purchases. Eventually I'd like to get additional useful instruments as I start needing them like a centrifuge and/or autoclave. But I probably won't ever get a FT-IR for example.

• What's the cost differential you're looking at? Apr 28 '17 at 13:42
• Around $800. So 0.1 mg balance would be about 2x price. Apr 28 '17 at 15:42 ## 2 Answers Either of these balances will require some care to set up. It will need to be on a solid surface away from any drafts, etc. However, neither would have the more expensive setup and maintenance requirements of say a$\pu{0.001mg}$balance. And in either case you can take care of the cleaning and calibration yourself, particularly as it's just a hobby with no certification requirements. I would seriously consider looking at used equipment from a place like LabX (I have no affiliation whatsoever). I would hesitate to purchase a used$\pu{0.001mg}$balance because that is a very sensitive piece of equipment, but a$\pu{0.1mg}$analytical balance; my lab always bought that sort of thing used. You can probably get a good used$\pu{0.1mg}$Mettler for example for the same or less than a new$\pu{1mg}$balance and there is really no downside. It's easy to imagine you wanting to weigh out a few mg of some reagent and having the ability to do that with the extra accuracy of at least a$\pu{0.1mg}\$ balance would probably be desirable.

• Thanks for the link. LabX looks great. I plan to get much of my equipment used, but I'm fine with buying a new balance. I was looking at the Ohaus AX series. Apr 29 '17 at 1:27
• I'm glad it was helpful. I really can't speak to Ohaus directly, but I knew other labs that used them and I never heard complaints (and lab people do like to complain about troublesome equipment ;) Best of luck. Apr 29 '17 at 1:31

Analytical balances require special care in setup (e.g. air current shielding) and some maintenance so if you think the environment is going to be a bit more "rough and tumble" it might not be worth the money. Given the price differential, I think the prudent move would be to purchase the precision balance.