A pipette is a common laboratory tool that everyone usually uses to prepare standards and measure liquids. However, this reality is often encountered in some laboratories such as chemistry, that is, there are still quite a number of laboratory or experimental personnel Be skeptical. The direct performance is to think that pipettes, better than pipettes, cost more. Therefore, here I would like to make a simple comparison between the two.
First of all, in terms of comfort of use, pipettes are better than pipettes. Nowadays, the design of the hand-held pipette has more and more incorporated ergonomic principles, which makes the pipette more convenient to use and more humanized.
Secondly, in terms of measurement accuracy, the accuracy of pipettes is much higher than that of pipettes. Today's micro-volume pipettes can measure up to 0.1 microliters, which are enough to replace pipettes in demanding experimental activities. In fact, for many demanding experimental activities, the accuracy of the pipette cannot meet the requirements. This mainly comes from two aspects. First, the pipette is generally made of glass, and the thermal conductivity of glass is higher than that of the plastic shell of the pipette. That is to say, the external temperature will be directly transmitted to the pipette inside the pipette. liquid, resulting in a change in its volume; second, because the glass tube wall of the pipette itself has a thickness, and the glass cannot completely avoid the refraction of light during the transmission of light in the glass, therefore, from the outer surface of the pipette The observed liquid height differs from the actual liquid height. And because of these two differences, there are different designs of pipettes, which are almost completely avoided.
So in terms of comfort and measurement accuracy, pipettes are stronger than pipettes, but people use pipettes a lot and are familiar with them, which has caused such a misunderstanding. The basic principle of the pipette's work is that the piston realizes the suction and discharge of liquid through the telescopic movement of the spring. Pushed by the piston, part of the air is removed, and the liquid is sucked in under the action of atmospheric pressure, and then the air is pushed by the piston to discharge the liquid. Due to the elasticity of the spring, the speed and force of the pipetting can be well controlled if the pipette is operated with this feature of the spring. Therefore, it is not difficult to see the application advantages of pipettes.