Posted on 20th Apr 2018
What does TD and TC on graduated glassware mean?
Some volumetric glassware bears the label "TC20˚C" which stands for "to contain at 20˚C".
This means that at 20˚C, that flask will have precisely the volume listed inside it. If you were to pour out the liquid, you would need to get every drop out of it to have that volume.
Alternatively, some volumetric glassware bears the label "TD20˚C" which stands for "to deliver at 20˚C".
This means that at 20˚C, precisely the volume listed will leave it when the content are allowed to drain out of the vessel.
It is not necessary to get every last drop and, in fact, it is inaccurate to blow the last bit out of a volumetric pipette.