The Vacuum Pump was invented by Otto von Guericke, who was a German scientist, inventor, and politician in 1650. Of course his Vacuum Pump was very primitive compared to the ones we use today: Onno’s Pump consisted of a piston and an air gun cylinder with two-way flaps designated to pull air out of any vessel it was linked to.
It is a device that get rid of gas molecules out of a sealed volume in order to leave behind a partial vacuum.
Vacuum pumps are today used in many processes, both industrial and scientific, and some of these include: Electron microscopy, Hard coating for engine, Sewage systems, Vacuum engineering, Air conditioning service and Medical applications like Radiotherapy, Radiosurgery and Radiopharmacy.
Depending from the usage, you can use different kinds of vacuum pumps in sequence or in parallel.
If you are not sure which type of Vacuum Pupm you need, first of all think for which application you want to use it (aspiration, centrifugal concentration, rotary evaporation, filtration, vacuum oven, reactors, etc..); then if you worry about the deep, remember that the deepest level achievable by a vacuum pump is idicate with the term “Ultimate vacuum”, so if you find one that has an ultimate vacuum of 60mbar it means that is capable of vacuum levels between atmospheric pressure and 60mbar.
About the flow rate required (the volume of gas/vapor it can move per unit of time), remember that is determined by a number of different factors, including the system leakage, time requirements, application’s vapor volume.
If you are looking for good Vacuum Pump Deals, you will probably find the best price online, and I suggest you to always visit not only the official brand website, but also online store that have different brand, because they often offer good discounts.
There are also a couple of tutorials online about how to make a vacuum pump at home, but I don’t suggest you to try doing it until you are not familiar with this kind of stuff and remember to always operate in completely safe enviroments.