Para calcular la calificación general por estrellas y el desglose porcentual por estrellas, no usamos un promedio simple. Nuestro sistema toma en cuenta cosas como lo reciente que es una calificación y si el revisor compró el producto en Amazon. También analiza las calificaciones para verificar su fiabilidad.
Excelentes pipetas graduadas, son resistentes, faciles de lavar, llegaron completas y el precio es razonable. Claro esta que no son para uso en laboratorio, si no mas bien para medir cantidades en la cocina.
I can't tell you how precise these are; I'm not working in a lab, but Bomex seems to make pretty accurate tools for an amateur chemist like me. I've combined these with a serological pipette controller (check out Levo's model for around $25) and it's like magic. I plan to throw the included bulbs away soon, but the pipette cleaning brushes are wonderful. With the pipette controller I can pickup precise amounts of fluids and deposit them at my leisure, then clean and reuse these glass pipettes. They will chip on the tips if you're not careful or break entire if you're reckless; I just bought a second set to have backups. For $15 shipped, this set is worth every penny. I hope this helps you.
Ya get what's you pay for. These are cheap. Only by the grace of baby Jesus and Opera Winfrey did they make it un broken bouncing around in the box, non were wrapped or protected. The problem lies in the suction. 3 of the suction balls don't make a air tight seal and therefore don't draw anything up the tube. I'd spend a few more bucks and buy something a little more professional next time.
I went on Youtube and learned how to use these, and it shows people putting the bulb on, filling it up more than the amount they want, then removing the bulb and swapping in their thumb. It's one quick movement with both hands. Then they slightly release their thumb until it reads at the amount they want, they hold that, then finally lifting their thumb, they add that amount to the destination. So getting the bulbs off while you're right in the middle of the process should not be tricky. That's the problem with half of these, the three, flared-top smaller ones with red bulbs. The blue bulbs and larger three work fine together. It's possible with the smaller ones, but I end up using the bigger three, which happen to work for my project, but if you need the smaller sizes, their might be a better choice somewhere.