When it comes to obtaining the accuracy for any analytical balance, calibration becomes an important consideration. A balance needs to have an accurate test weight in order to be capable of calibrating itself. The way that you handle calibration is by giving a base point, which should be zero, and then establishing the full capacity weight for the balance, which is known as Span. Became span is typically the maximum capacity for the balance, you are essentially giving the analytical balance two different but precise extreme points, which are full scale and zero. Now the balance is going to be capable of accurately calculating any amount between these two points, which are base point, or zero, and full capacity or span. Some analytical balances offer a calibration feature that can be selected for individuals that want to calibrate their balance to a weighing capacity that is less than full capacity of that balance. What this means is that the user plans to weigh items less than the balance’s designed full capacity, and would like a more precise and accurate reading. When you calibrate analytical balances to a span that is closer to the actual maximum capacity intended for the user, then a more accurate calibration will be able to be achieved. For example, if an analytical balance is purchased with an ability to weigh as much as 6000g using a 0.1g readability, but the user only intends to weigh items up to a maximum weight of 4800 grams, then the user can calibrate the balance to a full capacity of 5000g in order to improve the accuracy of the device through a customized calibration mass. While this calibration configuration does allow for heavier weights to be measured, it enables a much more accurate result in weighing items at or near 5000 grams. When it comes to calibrating analytical balances, it is important to know that balances can be influenced by a number of factors including changes in humidity, seasonal temperature, barometric pressure and also gravitational acceleration, which is described as your location in relation to magnetic north. For this reason, if the maximum level of accuracy is desired, it has become necessary for users to calibrate their balance when it is initially being installed, as well as after the balance changes locations. It is also generally recommended that balances be calibrated on a regular basis simply to ensure that they maintain the most precision possible. It is useful to have a number of different values of calibration mass on hand so that calibrations can be performed whenever they are needed. Many manufacturers of analytical balances actually recommend that the calibration mass be purchased at the same time that the balance is purchased in order to make sure that the balance is always capable of being calibrated properly as needed. It is important to have the right type of calibration mass on hand so that an accurate calibration can be achieved, so that weighing results are never called into question.