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Why do pipettes have bulges?

Why do pipettes have bulges?

Why is it shaped the way it is? By having a bulge in the midsection like some middle-aged man, it holds the bulk of its volume there. The desired volume delivered from the pipet is calibrated by taking that trapped volume into account, and so it should not be forced out. The proper use of the pipet leads to precision.

Are pipets volumetric?

Volumetric Pipettes are designed to very accurately transfer a specific amount of solution. These pipets can only be used to deliver the volume of liquid for which it is calibrated. Volumetric pipets have narrow tips and a bulb-like expansion in the middle.

How do you read pipette measurements?

Numbers on the micropipette (typically black-black-red) are read as XX. X µl. The change in color indicates the position of the decimal point. P200: Maximum volume 200 µl.

What is a pipette bulb?

Flexible, variable-capacity bulbs that are squeezed to create a vacuum or apply pressure to the liquid contents of pipets to collect, transfer, and dispense liquids; available in various styles and materials.

What are Class A pipettes?

Class A pipets are manufactured to provide high accuracy and they are required to meet the requirements and tolerances in ASTM E969 − 02 (Reapproved 2012) “Standard Specification for Glass Volumetric (Transfer) Pipets.”

How accurate are Volumetric pipettes?

Volumetric pipets, sometimes called transfer pipets, are the most accurate pipets. They generally deliver the specified volume ±0.1%, an error of a few hundredths of a milliliter. They are much like burets and can be used for small volume titrations.

What is the least measurable quantity in a 10 ml volumetric pipet?

If you look at a 10mL graduated cylinder, for example, the smallest graduation is tenth of a milliliter (0.1mL). That means when you read the volume, you can estimate to the hundredths place (0.01mL).

Why is volumetric pipet more accurate?

The main advantage of a volumetric pipette is its accuracy. It is especially precise when it is delivering solutions, as another advantage of the standard build is its narrow neck. This allows for the meniscus to be read more accurately, and therefore deliver more precise results than graduated pipettes.

What are the different sizes of micropipettes?

Choosing the micropipette We use three different sizes of micropipettes in the laboratory, the P20, P200 and P1000. Our micropipettes have been purchased from several different manufacturers, but the principles of operation are the same.

What is the main function of pipette bulb?

It is either made of glass or plastic, has a round bulge near the top of the pipette body to disperse the bubbles in the liquid, and can measure foamable liquids safely. A rubber bulb is usually attached to the top of the pipette to act as a pump to aspirate and discharge liquid.