While lab scales examine the mass of a single object or group of objects, balances compare the mass of two sets of objects. In a laboratory, an accurate balance can be essential to your research and its accuracy. Whether you are shopping for a balance for the first time or considering adding one to your collection, here are some attributes you should look for in a balance and a few things to keep in mind as you start weighing objects:
1. Enclosed Weighing Pan
If you want to be sure the samples with which you are working are weighed accurately, consider purchasing a balance with an enclosed weighing pan. The enclosure protects the pan so that mud, dust, and even tiny microbes do not get onto the sample. This layer of protection ensures that you get an accurate weight, keeping your research correct and on track. So that you can access the weighing pan, the enclosure should have doors, and it should be made from a clear material.
2. Spring Force Adjustment
Instead of moving weights on or off the balance beam to determine the weight of the object being measured, look for a balance that calculates the final balance through the use of a small spring mechanism.
When you use a balance, you typically move small weights onto or off one side of the balance, and the amount of weights you use indicates the weight of the object you are measuring. However, if you want the most accurate weight possible, you should look for a balance that allows you to add weight only until you are close to correctly identifying the weight of the object. At that point, instead of adding or subtracting more physical weights, you calculate the final weight by carefully turning a knob attached to a special spring force mechanism.
3. Multiple Applications
Whether you are buying a beam balance, a spring balance, a top-loading balance, an analytic balance or a precision balance, look for one that has multiple applications. The more your balance can do, the more of an asset it will be to your laboratory. Some of the extra applications you may want to look for include percentage weighing, piece count, statistics generation and density measurements.
A percentage measurement feature allows you to weigh several items with the balance, and it alerts you when you have added the correct percentage of a certain material to the mix. For example, if you were following a recipe for a special substance and the relationship between the elements in the recipe were expressed as a percentage, this feature would be invaluable. This feature allows you to add x amount of one ingredient, and then, based on the weight of that ingredient, the balance directs you toward the correct amount of the other ingredients in the recipe.
A piece counting function allows you to weigh one piece or a solitary object. Then, you can place a bunch of those objects on the balance, and it will tell you how many you have. Statistics generation tools take weights, masses, percentages and other figures, and they crunch these numbers on your behalf to generate the statistics you need.
In many cases, you need to consider not only the type of balance you are have or the features it offers. Rather, you need to think about the weighing process itself. Most importantly, make sure that you are weighing samples that are at room temperature. If the sample is too hot or too cold, convention will naturally occur. The convection will cause air currents, and these currents will make the weight look heavier than it is.