A 1 mL U-100 syringe holds 100 units. The markings run 10, 20, 30 and up to 100, with smaller ticks between them. Once you know which edge to read, the scale stops being decoration.
Read the plunger tip, not the liquid
The liquid forms a curved surface (the meniscus) and it will sit slightly off the mark. The accurate reading is the flat edge of the plunger inside the barrel — the line the rubber stopper makes as it travels. Line that edge up with the marking, not the top of the liquid.
Units to millilitres
100 units = 1 mL, so:
- 10 units = 0.1 mL
- 50 units = 0.5 mL
- 100 units = 1 mL
Divide the unit marking by 100 to get millilitres. That is all the conversion there is.
Take out the dead space first
Push the plunger fully in before drawing liquid. If you start with the plunger halfway out, the first part of the draw only fills the tip and the scale will read low.
Why bold markings matter
On a thin barrel, faint markings are the most common cause of a mis-read — especially under bench lighting. HENDARI prints the 10–100 scale in heavy contrast on a clear PP barrel, so the number you need is legible at arm's length.