Well no, it’s not a single person, but more like a rare person. How many people in the modern world own calibrating weights for scales? I don’t, and I’d actually need to calibrate my scales (I just check em with several coins to get more or less a known weight. But have to do several coins so it averages out the dents and dirt the coins might have.)

I’m just saying I don’t believe this accuracy is anything that would’ve been needed by an average citizen. So, not unique objects, but handmade specialised equipment. Probably most towns/cities would have only one or a couples of apothecaries, if any. These apothecaries on the other hand would have to get their specialised equipment either from knowing how to advice a craftsman how to make it, make it themselves, or get them from a bigger city.

I mean you still see the exact type of bottles in pharmacies as decoration. (Well we do here. I’ve gathered US pharmacies are a bit more… commercial.)

https://en.m.wikipedia.org/wiki/Apothecaries'_system#Origin

https://en.m.wikipedia.org/wiki/Ancient_Roman_units_of_measurement

I’m thinking they’re some of these:

Idk how lemmy will format but the numbers after mean unit, equal to, metric, imperial and US fluid:

acetabulum 1⁄48 congius 68 mL 2.39 fl oz 2.30 fl oz

quartarius 1⁄24 congius 136 mL 4.79 fl oz 4.61 fl oz

hemina or cotyla 1⁄12 congius 273 mL 9.61 fl oz 9.23 fl oz

sextarius 1⁄6 congius 546 mL 19.22 fl oz 0.961 pt 18.47 fl oz 1.153 pt

congius 1 congius 3.27 L 5.75 pt 0.719 gal 3.46 qt 0.864 gal

urna 4 congii 13.1 L 2.88 gal 3.46 gal