Handling and measurement
Unit (Syringe Unit)
Last updated
One mark on an insulin syringe barrel. On the usual U-100 barrel one unit is one hundredth of a millilitre, or 0.01 mL, so a hundred of them fill 1 mL. A 1 mL barrel is normally printed with a numbered line every 10 units and a small line every 2 units, while the smaller 0.3 mL barrels usually give a line for every single unit. A unit is a measure of how much liquid and nothing else.
Why it matters here
Almost every number people exchange informally about drawing up is said in units, and a unit only means something once you also know the scale of the barrel and the concentration of the liquid in it. Missing either one turns a shared number into a guess, because the same count of marks holds different volumes on different barrels and different amounts of substance in different vials.
What it is not
A syringe unit is not an International Unit. They share the word unit and share nothing else: the mark on the barrel is a volume, while an IU is a measure of biological activity defined separately for each substance. A label reading in IU and a syringe reading in units are not the same scale and cannot be read across.
Also called
- unit
- units
- syringe unit
- syringe units
- insulin unit
- tick
- ticks
Tick and line are informal names for the printed mark itself. Click is borrowed from dosing pens, which move in stops you can feel, and it is misleading for a syringe because a plunger slides smoothly and has no stops.
Compounds carrying this term
None on file yet. This term is in the controlled vocabulary but no compound record currently uses it — which is a statement about our coverage, not about the term.