When it comes to measuring volume, there is a vast array of laboratory glassware available.
But why?
Is there really a need for all the different sizes and shapes when you consider they all perform largely the same function, which is to hold liquids.
The majority of glassware used in a lab will also have graduations, which allow the user to measure the volume of liquid in the receptacle.
However, despite the similarities of scientific glassware, certain pieces are used for specific purposes. We examine some of the most commonly used laboratory glassware items and explain their functions.
Beakers and Flasks
Whether you walk into a school science lab or a high-end research laboratory, one item of glassware you’re almost guaranteed to see is beakers and flasks.
Both of these items are primarily used for storing liquids rather than measuring volume. They come in a broad range of sizes and are relatively low-cost.
Beakers are generally little more than glass jars with a small spout for pouring out the contents. Most beakers will have graduations marked on the outside, but they lack accuracy, and therefore, they should not be relied upon when precision is vital.
Erlenmeyer flasks, otherwise known as conical flasks, have a wide, flat bottom and an inverted cylindrical neck. They have a rimmed mouth to make pouring easier, and rubber stoppers can be used to seal the flask. As well as storage, Erlenmeyer flasks are used for mixing liquids as their narrow necks reduce the risk of spillage.
Graduated Cylinders
Graduated cylinders are made specifically for measuring volume. Their markings on the outside allow for accurate measurements.
They are available in a comprehensive range of sizes from 5ml at the lowest end up to 2000ml. A wide, flat bottom ensures stability, and a small spout helps when pouring the contents of the cylinder.
The level of measurement accuracy is better than that of a beaker or flask. However, there can be a 1% discrepancy. If a highly accurate measurement is required, then a graduated cylinder may not be suitable.
Burettes
Burettes, along with Pipettes, are part of a category of products known as volumetric glassware and are highly accurate when measuring volumes.
They are cylindrical in shape and have graduations printed on the outside. They are used for measuring smaller volumes of liquids and come in standard sizes of 10ml, 50ml and 100ml.
Unlike the other items on this list, burettes have a stopcock or valve at the bottom that allows the contents to drain out. They are used for experiments that require a high degree of accuracy, such as titration experiments.
Measuring Volume – Summary
The item of scientific glassware you choose will depend upon the level of accuracy you need to achieve in your experiments. If you are unsure which type of piece you require or would like to discuss a bespoke item, then please get in touch with our team. Our expert scientific glass blowers have many years of experience in creating custom-made items and can advise on which type of glassware will be most suitable to accomplish your aims.
Ken founded Scientific Glass Services in 1978 and has a wealth of experience developing custom-made scientific glassware, working closely with research laboratories, hospitals and universities. Ken and the team make bespoke laboratory glassware to your requirements or repair valuable broken apparatus, each piece being hand-blown from quality borosilicate glass.