With such a wide variety of scales available, it's hard to know which one will be best for a classroom setting. A high-quality scale is a great addition to any school laboratory, but the type of scale that would be useful for a pharmaceutical or other professional setting may not be the same type that will be useful for a chemistry or physics class. It all depends on what you'll be using it for.
Digital scales are great for accuracy and ease of use, but ease of use may not be your highest priority in a classroom. Digital scales are so automatic that, although they are useful for getting a good reading, they will not provide a student with the direct, hands-on experience of weight, mass, and force that an analog scale will. It's also true that you can buy digital scales that are built to output their data to a computer, which is useful for professional applications; but again, in a science classroom, the practice of gathering and analyzing data is a valuable tool for students to have, and they won't learn it if it's done for them by a machine.
If you decide to buy an analog (or mechanical) scale, you have several options. There's the classic triple-beam balance, which not only can give measurements accurate within 0.1 gram, but also provides visible lessons on the principles of balance — as the students move the sliders to the right, they will see that a mass positioned further from the fulcrum will increase the downward pull.
If you are introducing your students to the concepts of weight and mass, you may want something a bit more direct: a simple balance with a mass set. The mass sets are often quite elegant, and provide a good way to familiarize your students with the units of mass — they can see for themselves what the heft of a kilogram is. For those who want a precision balance, it's likely a
precision balance laboratory scale can give you the best in accuracy and reliability.
For studies of gravity, spring tension, and weight, you may want to get a spring scale. Watch the quality on these, though: cheap spring scales can lose tension fairly quickly, rendering them useless. Some spring scales come with a set of hooked masses. It's a good way to concretely illustrate the concept that gravity does in fact exert a force on every object, proportional to its mass.
Whatever scale you decide to purchase, bear in mind that it should be both durable and accurate. Accidents happen, and you want your balance to be able to handle some potentially rough treatment. And while accuracy in the classroom is arguably less important than accuracy in the laboratory, it's embarrassing (and a poor demonstration of true scientific method!) to have to "correct" your measurements in order to get them to line up with reality. If you're looking for the best in
college laboratory scales, you can buy online and save a lot of money.
