Absolute precision is needed in a scientific research environment. Temperatures, timings, and weights and measures of every sort must be followed accurately and methodically, ever-vigilant meticulous care must be taken to obtain repeatable results, and to experiment with confidence. As far as weight measurement goes, the only choice for this absolute perfection in measuring would be the symmetry balance scales.
Analytical balances must have functionality as well as accuracy. Accuracy is the most vital part of the scientific balance scales purpose, as even the smallest amount of error can lead an experiment to disaster. When weighing dry measures, such as powders, the accuracy of the scale must be so complete that even a dispersion of the powder settling on the scale platform should register on the display.
This sensitivity leads us to consider what may interfere with such a precision instrument as a symmetry balance scale. Does temperature affect the weight measurements? Is a drafty laboratory a significant problem when using the balances? Will moisture in the air cause problems while weighing? These simple questions must be asked when deciding on a new scientific balance scale for your laboratory.
An excellent balance will have a zeroing capability that only takes less than five seconds, and a readout time of the same amount of time. This may be necessary for efficiency in the laboratory, as data may need cataloguing constantly. To make this easier for the laboratory personnel, a printer port attached to the balance may be used, and good scientific scales should have this function built in. An excellent weighing system may have laboratory information systems integration, so that weights can be linked to the laboratories computer system for absolute quality control.
The digital age has arrived for scientific balances, as the digital readouts of these new systems are usually liquid-crystal displays backlit for easy reading. Digital filters allow for vibration, temperature, and draft while measuring out the items, all for flawless weight measurement of nearly anything needing weighing. A good balance will have shielding on three sides of the scale to stabilize the air before placing the items on the weighing platform.
Other characteristics of an excellent weighing system, especially in these balances, would be fast stabilization prior to weighing. Stabilization times should be short after switching the unit on, so wait times are reduced. After stabilization, there should be an easy tare zeroing function, especially when using a container other than what came with the unit. Tare zeroing is vital to getting exact measurements of any material, and should be reproducible each time the container is used.
Item counting can be highly beneficial to the laboratory personnel when weighing out pellets of materials, or small items needing stocking that otherwise would need to be counted by hand. An accurate balance scale can provide a counting function, by weight of the individual item being counted in quantity. This should be easy to obtain, as an individual item is first weighed, then tared for counting. This should be done in seconds, and as more of the same item is added to the symmetry balance, the count will be accurate to within only one to two items.