1. A volumetric pipet is stamped by the manufacturer with “TD 25 10 mL”. Explain what this means.
2 answers
It means "To Deliver". When used the pipet still will have some liquid inside at the end. You do NOT blow that out because it has been calibrated To Deliver th 25 mL and leave some behind.
Sometimes the pipet is market "TC". That means "to contain". So a 25 mL pipet marked TC means that you touch the tip of the pipet to the inside of the transfer vessel and when it stops delivering, there will be a small amount left tip of the pipet. You gently blow out the last bit at the bottom in the pipet.