You may think that all it takes to read a syringe is to look at the lines on the tube. However, different syringes measure volume in different increments and sometimes they do not use the standard milliliter (ml). This can make reading the syringe more difficult than it seems! Always start by double checking the unit of measurement for the syringe and the value of each line on the tube. To get an accurate measurement, all you need to do is fill the syringe and push the pump up to the required amount.
Step
Part 1 of 2: Measuring through the Marks on the Syringe
Step 1. Check the syringe unit
There are various sizes of syringes. Most syringes are clearly marked in milliliters (ml). You will see a mark in the form of small lines on the syringe tube. Each marks a specific amount in milliliters or fractions thereof.
- Some syringes, such as those used to measure insulin, are marked with various "units" other than milliliters.
- Some older or non-standard syringes may also use different units.
Step 2. Count the lines on the syringe marked with even increments
For example, you might have a syringe with outline markings at 2 ml, 4 ml, and 6 ml. Halfway between each of these outlines, you will see a slightly smaller line. Between each numbered line and a slightly smaller line, you will see 4 lines of even smaller size.
- Each such smallest line counts as 0.2 ml. For example, the first line above the 2 ml line is equivalent to 2.2 ml, the second line above it is equivalent to 2.4 ml.
- The medium-sized line in the middle of each number equals the odd number between them. For example, the line between 2 ml and 4 ml equals 3 ml, and the line between 4 ml and 6 ml equals 5 ml.
Step 3. Read the syringe markings in sequential increments
For example, syringes may be marked with a number in each ml successively. Between them you will see a medium-sized line marking ml units, such as 0.5 ml, 1.5 ml, 2.5 ml, etc. The four smaller lines between each line marking ml and 1 ml are equal to 0.1 ml.
- Therefore, if you need to measure 2.3 ml, draw the liquid up to the third line above the line marking 2 ml. If you were to measure 2.7 ml, the scale would be on the second line above the line marking 2.5 ml.
- Your syringe may be marked in other increments, such as multiples of 5 ml or in 1 ml fractions. If so, the principle is still the same - just look at the main numbers on the syringe, and calculate the value of the smaller lines between them.
Step 4. Take measurements between the small dashes if necessary
Sometimes you will be asked to measure a certain amount that is not clearly marked on the syringe. To do this, calculate the unit value between the lines.
- For example, let's say that you are asked to measure 3.3 ml of a drug, but the available syringe is marked by a small line whose value is equivalent to an increase of 0.2 ml.
- Draw the liquid medicine up to fill the syringe tube, then push the pump until the medicine reaches the line between 3.2 ml and 3.4 ml.
Part 2 of 2: Using the Syringe Accurately
Step 1. Hold the syringe by the flange
Hold the syringe by the wing on the top of the tube opposite the tip. This part is known as the flange. Holding the syringe this way helps keep your fingers out of the way when you're trying to read it.
Holding it this way is also important for super-precise scientific measurements to ensure body heat from the fingers doesn't change the fluid content being measured using the syringe. You don't have to worry about distortion due to body heat for everyday measurements (eg home remedies)
Step 2. Fill the syringe more than needed
Always use a syringe that is larger than the number required for the measurement. Dip the needle into the liquid to be measured, then slowly withdraw the pump until the syringe is filled beyond the line value required for measurement.
For example, if you want to measure 3 ml of children's medicine, use a syringe with a capacity of 5 ml or more. Withdraw the pump until the liquid fills the syringe and has exceeded the line marking 3 ml
Step 3. Push the pump until the liquid is at the line value required for measurement
While still holding the syringe in your hand, gently push the pump back with your thumb until the liquid reaches the point required for measurement.
For example, if you want to measure 3 ml of medication, push the pump on the syringe until it reaches the line indicating 3 ml
Step 4. Read from the top ring of the pump
Regardless of which syringe is used, always pay attention to the part of the pump that is closest to the tip of the syringe when reading it. This is the part that touches the liquid being measured. The part of the pump closest to the top of the syringe is irrelevant and is not intended for measurement.
Warning
- Some syringes can be marked by more than 1 unit, for example tsp and also ml. Make sure to always be consistent and only use 1 set of unit lines.
- Do not attempt to measure using a syringe marked with a different unit than instructed. For example, don't try to guess and measure the ml unit using a syringe that only has a tsp scale. This step may result in inaccurate readings.
