I am thinking of buying a used analytical balance with a sensitivity of around 0.0001g. Something very similar to this --> http://www.coleparmer.com/Product/Cole_Parmer_Symmetry_PA_Analytical_Balance_120g_x_0_0001g_115_VAC/EW-10000-15 .

 

If I buy it used, perhaps 7-8 years old, what potential hardware issues could it have? I am not familiar with this kind of equipment. How fragile is it?

 

TIA

Very hard to tell and depends (obviously) how well it was treated. Typical issues are stuff getting below the weighing platform and forming crusts or causing corrosion.

For the most part they are quite sturdy and I have used much older instruments that still worked fine after calibration (the oldest must have been from the 50s though at some point a gear broke).

Assuming it was not abused and buried in a thick layer of gunk it should be fine. If possible I would ask for close-up images especially of the platform and the parts below for visual inspection.

Whilst the 100g mass is a desireable accessory, you can improvise if you have access to another balance, by weighing something you can keep for the future, eg a box of lead shot, and comparing. You could actulally make and prepare several test weights this way.

The 100g g test weight is obviously needed for commercial applications.