[media = https: //www.youtube.com/watch? v = 4v3N3hEmodY]
Often, pipettes are used to pour a small amount of liquid, which can be bought at a pharmacy. Using pipettes, you can measure the amount of liquid dropwise. But when you need to measure the liquid drop by drop, but there should be a lot of drops, it is not very convenient to use an ordinary pipette. You can make a homemade pipette, with which you can easily pour a large number of drops of liquid.
For homemade will need syringe. Choose the size of the syringe yourself, based on the calculation of how many drops a pipette is needed.
Using a clerical knife, carefully cut off the part of the syringe that served for the needle:
Next, we need to use any alcohol solution to erase the scale on the syringe, which we do.
Now we will calibrate the new pipette, that is, apply the appropriate scale to the syringe. To do this, we draw liquid into the syringe.
We mark with a felt-tip pen the division where the liquid ends:
After that, 10 drops are carefully counted from the collected syringe and after that we mark the second division on the syringe
Next, using a caliper, measure the exact distance from the first division to the second (that is, in this way we find out how much space in the syringe takes 10 drops):
Now on the piston using the same caliper we mark the divisions that correspond to 10 drops.
Thus, we further mark the piston on the syringe:
After we have done the division, they need to be signed with the appropriate numbers.
Now you can use the scale applied to the piston to measure the exact number of drops that will be needed, and carefully use the syringe as a pipette.
