There are many factors to consider when we design and use an electronic balance such as the Lab Electronic Balance, the most important of which is the stability of the balance, the sensitivity of the balance, the correctness of the balance and the invariability of the value of the balance. The so-called stability is the stability of the balance precision; The sensitivity refers to the reaction speed of the balance reading. In this aspect, electronic balance has higher sensitivity than mechanical balance. Correctness is the accuracy of its readings; The invariance refers to the stability of the balance reading, namely the floating range of the balance reading. The smaller the floating range, the better the invariance. Here is a detailed look at the four indicators.
1. Stability of the balance
The stability of the balance is the ability of the balance to automatically return to its initial equilibrium position after being disturbed. For electronic balance, its balance position is always represented by the indication value of analog indication or digital indication. Therefore, once an instantaneous disturbance is applied to the electronic balance, the indication value changes, but after the disturbance is removed, the balance can return to the original indication value, then we say that the electronic balance is stable. For an electronic balance, the stability of the balance is the primary criterion for the use of the balance, and the electronic balance without the stability of the balance cannot be used at all.
2. Sensitivity of the balance
The sensitivity of a balance is its ability to detect changes in the mass of the object on which it is placed.Also called Precision Balance. The sensitivity of the balance may be indicated by the angular sensitivity, or the linear sensitivity, or the graduated sensitivity, or the digital (graduated) sensitivity. For electronic balance, it is mainly expressed by dividing sensitivity, or digital (dividing) sensitivity. The smaller the quantity of mass change that can be detected by the balance, the more sensitive the balance is. It can be seen that for electronic balance, the sensitivity of the balance is still one of the important properties for judging the advantages and disadvantages of the balance.
3. Correctness of the balance
The correctness of the balance is the correctness of the value of the balance. From the perspective of error, the correctness of the balance is the degree of systematic error reflecting the value of the balance.
For the lever balance, the correctness of the balance is mainly reflected in the accuracy of the arm ratio. However, whether it is a mechanical balance or an electronic balance, the correctness of the balance is also reflected in the correctness of the display value of the analog scale or the digital scale of the balance, as well as the display value of the load placed on each point of the balance measuring plate.
4. Invariance of the value indicated by the balance
The invariance of the indicated value of the balance refers to the consistency of the measured results of the same object repeatedly measured by the balance under the same conditions.
For the electronic balance, there is still the invariance of the value indicated by the balance, such as the control of the repeatability and reproducibility of the electronic balance, the control of the zero and zero return error of the electronic balance, and the control of the drift of the value indicated by the balance in the specified time (such as 4 hours of loading) when the electronic balance is empty or loaded.