How do you read a measuring cylinder?

Bring your eye level with the surface of the liquid, work out what each division is worth, and read the scale at the bottom of the meniscus to the nearest half division.

Where do you read the meniscus?

For most liquids, including water, read at the bottom of the curved surface, at the centre of the cylinder, not where the liquid climbs the glass.

What is the uncertainty of a measuring cylinder reading?

It is usually taken as half the smallest division. A cylinder with finer divisions gives a smaller percentage uncertainty for the same volume.

Measuring cylinder and meniscus reading practice

Practise reading the volume in a measuring cylinder at the bottom of the meniscus, on cylinders with different scales. It's free to use, with no sign-up.

Read the volume of liquid in the cylinder, to the nearest half division. Each new reading may use a different cylinder, so check what each division is worth first.

How to read a measuring cylinder

Stand the cylinder on a level surface, and bring your eye level with the surface of the liquid.
Work out what each division is worth: the gap between two numbered marks, divided by the number of divisions between them.
Read the scale at the bottom of the meniscus, the lowest part of the curved surface, to the nearest half division.

For example, on a 0-50 cm³ cylinder there are 10 divisions between the numbered marks 10 cm³ apart, so each division is 1 cm³. If the bottom of the meniscus sits halfway between the 34 and 35 cm³ marks, the volume is 34.5 cm³.

The meniscus and uncertainty

Water and most other liquids climb the glass, curving upwards at the edges. This curve is the meniscus. Read at the flat bottom of the curve, not where the liquid touches the glass.

Reading from above or below makes the surface appear against the wrong mark (parallax), so your eye should be level with the bottom of the meniscus. The uncertainty of a reading is usually taken as half a division. A narrower cylinder, with finer divisions, gives a smaller percentage uncertainty for the same volume.

Common mistakes

Reading the edges of the liquid, where it climbs the glass, rather than the bottom of the curve.
Assuming each division is 1 cm³ without checking.
Viewing from above or below the level of the liquid.
Miscounting the divisions from the last numbered mark.

Frequently asked questions

How do you read a measuring cylinder?: Bring your eye level with the surface of the liquid, work out what each division is worth, and read the scale at the bottom of the meniscus to the nearest half division.
Where do you read the meniscus?: For most liquids, including water, read at the bottom of the curved surface, at the centre of the cylinder, not where the liquid climbs the glass.
What is the uncertainty of a measuring cylinder reading?: It is usually taken as half the smallest division. A cylinder with finer divisions gives a smaller percentage uncertainty for the same volume.

Practise it in a full required practical

LabWizard walks A-Level Physics students through simulated required practicals, from taking measurements with instruments like this one to graphing, analysis and exam questions. This skill is used in the Boyle's Law, Charles's Law practicals.

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