What are the methods of pipette calibration?

The calibration of pipette is carried out by gravimetric method. When determining the volume of water, the accuracy of measurements is effected by ambient temperature, atmospheric pressure and relative humidity. These factors are usually combined to give the Z factor, used in calculation of volume of water.

How do you calibrate a pipette a level?

Pre-rinse the tip by aspirating and dispensing the set volume three times and push fully to remove any remaining liquid. Aspirate the calibration volume without bubble formation and dispense the liquid slowly into the weigh boat. Then, record the weight on the balance and repeat the process ten times.

How do you calibrate a pipette titration?

Calibration of single volume pipettes Pipette water into the bottle, close, weigh again. Mass difference is the mass of water. Repeat 3-4 times. In both cases use your results to calculate average mass.

What is the purpose of calibrating a pipette?

Pipette calibration is necessary to prevent inaccuracies in order to attain better results, performance, and longevity of the pipette itself.

How does temperature affect pipette calibration?

The warming of the pipette tip causes the captive air to expand and push liquid from the tip. Less liquid is aspirated and subsequently dispensed, leading to a variation between the target and delivered volumes. The captive air volume shrinks, causing more liquid to be aspirated and subsequently dispensed.

How do I know if my pipette is calibrated?

The Weight of Water The most common way to check your pipette accuracy is by weighing water. The density of water is 1 g/mL. This means that every microliter (µL) should weigh 0.001 g. In other words, if your pipette is accurate, the amount of water you dispense will equal the amount the water weighs.

What is the purpose of calibrating a 5 mL volumetric pipette?

For this purpose, it is desirable to calibrate your own volumetric glassware (burets, pipets, flasks, etc.) to measure the exact volumes delivered or contained. This experiment also promotes improved technique in handling volumetric glassware.

How is a volumetric pipette calibrated?

Liquid is drawn through the tip of the pipette, filling a bulb in the body of pipette, until the liquid level reaches the calibration mark. The measured liquid is then drained for use. Volumetric pipettes are never to be blown out.

What is the difference between Class A and Class B volumetric glassware?

Class A volumetric glassware has a lower tolerance than Class B; for class A, the tolerance can be as low as 0.08 ml for a 100 ml flask or pipet. Generally, measurements with class A volumetric glassware can be considered reliable to two places after the decimal point.

How often should I calibrate my pipettes?

As the manufacturer of MLA and Ovation pipettes, VistaLab recommends performing routine maintenance and calibration verification on pipettes at least once every 6-12 months (depending on how often they are used and what they are used with).

What is the process for Pipette calibration?

Common methods of pipette calibration involved setting pipette volumes and weighing the resultant liquid picked up by the pipette against the expected weight . Once this is within an acceptable margin of error for the laboratory, then the pipette passes calibration.

Why to calibrate your pipettes?

The more frequently calibration is performed, the sooner malfunctioning pipettes will be detected and taken out of service. In addition, more frequent calibration can help eliminate the need to review laboratory data to ensure that incorrect liquid delivery by a failed pipette has not compromised laboratory results.

Why to calibrate a pipette?

A pipette is used to precisely measure and transfer small volumes of liquid in the laboratory in experiments that demand high accuracy. It is, therefore, necessary to check pipette calibration every few months to ensure accuracy by dispensing right volumes.