In any well-equipped lab, various types of specialized glassware are used to measure and handle liquids. From pipettes for small volumes to beakers for larger quantities, each piece has a distinct purpose. Made from durable borosilicate glass, this labware is designed to withstand chemical reactions and high temperatures while providing accurate measurements.
The precision of each instrument varies—beakers and flasks are less precise, while graduated cylinders, volumetric flasks, and pipettes are used for exact measurements. In this post, we’ll review the essential instruments for measuring liquid volumes in the lab.
Erlenmeyer flasks have a narrow, cylindrical neck and a conical base with a flat bottom. Designed by Emil Erlenmeyer in 1861, these flasks are used primarily for mixing and heating solutions. They are typically made from borosilicate glass, allowing them to withstand high temperatures without breaking.
With a long neck and round bulb base, Florence flasks are similar to Erlenmeyer flasks in their ability to withstand heating, thanks to their borosilicate glass construction. These flasks are frequently used in boiling or distillation experiments.
Beakers are ubiquitous in labs, known for their cylindrical shape, spout for pouring, and measurements marked on the side. They serve a variety of purposes, such as creating chemical reactions and heating solutions over a Bunsen burner. While they offer basic volume measurements, beakers are not the most precise tools for accurate quantifications.
Graduated cylinders are tall, cylindrical containers designed for more accurate volume measurements than beakers. Marked with gradations along the side, these cylinders are commonly used to measure liquids in volumes ranging from 10 mL to 1,000 mL.
Volumetric flasks, also known as Dewar flasks after Sir James Dewar, are designed for high-precision measurements. These flasks have a long, narrow neck and a round bulb base, with a single hash mark that indicates the precise volume they contain. Volumetric flasks are commonly used for preparing solutions with exact concentrations.
Burettes are long, narrow tubes with precise gradations marked along the side. They are fitted with a stopcock that controls the flow of liquid, making them essential for titrations and other experiments that require the accurate dispensing of liquids. Burettes provide highly accurate volume measurements, typically used in chemistry labs.
Pipettes are essential for transferring liquids in small amounts. They come in various types, including serological pipettes, which can measure and transfer liquids ranging from less than 1 mL to up to 50 mL, and volumetric pipettes, which are designed for a single, precise measurement. Volumetric pipettes are highly accurate and often used in analytical chemistry.
Accurate volume measurements in the lab require careful technique. Here’s how to ensure precision:
Following these steps will help minimize errors in volume measurements, particularly when using volumetric glassware, which typically has very low tolerance for deviation.
Contaminants such as residual liquid, dirt, or grease can interfere with accurate measurements. It is crucial to thoroughly clean and dry labware before use to avoid errors caused by improper drainage or residue.
Liquid surfaces form a curved shape known as a meniscus, which can lead to measurement errors if not observed correctly. To avoid inaccuracies, always read the bottom of the meniscus at eye-level when measuring liquid volumes.
Many volumetric devices are calibrated for specific temperatures, usually marked on the glassware. For example, a volumetric flask might be calibrated to measure 10 mL at 20.0°C with an accuracy of ±0.02 mL. Ensure that your lab environment matches the temperature marked on the device for the most precise results.
Equipping a lab involves purchasing both costly specialized equipment and essential supplies like pipettes. While items like pipettes may seem small, the cumulative expense can take a significant chunk out of your budget. To save money and allocate resources more effectively, consider leasing equipment from Excedr.
With Excedr’s leasing program, you can procure high-ticket items without large upfront costs, keeping your lab's expenses under control. Whether you need volumetric glassware or more advanced instruments like spectrophotometers or centrifuges, leasing laboratory equipment with Excedr can help you get what you need without breaking the bank.
Contact Excedr today to request an estimate and learn more about how leasing can benefit your lab.
