How Should The Analytical Balance Be Used?
An indispensable important instrument in quantitative analysis work must be an analytical balance. A full understanding of instrument performance and proficiency in its use is an important guarantee for reliable analysis results. There are many types of analytical balances, including ordinary analytical balances, semi-automatic/automatic electro-optical analytical balances and analytical balances. At present, the laboratory routinely uses analytical balances with a high degree of automation. How to use analytical balances? What are the precautions?
General steps and precautions for the use of analytical balances.
The use of analytical balances has higher requirements, both for the personnel and the specific environment used, including the following points:
Choose the right balance
When choosing a balance, the first thing to consider is whether there are special requirements for the accuracy of the symmetry. Try to avoid using a balance with insufficient accuracy for weighing, and at the same time, avoid using a balance with too high accuracy. Weighing, resulting in waste of use. In addition, when choosing a balance, you also need to consider whether a large range can meet the weighing needs. Because depending on the specific use situation, the selection of the range should also be based on the application.
Preheating is still necessary
Preheating is required before weighing. This is not only the method of using analytical balances, but also one of its characteristics. Only after preheating, the magnetic steel will be balanced accordingly, and the balance will also be balanced. The most important thing during preheating is the need to control the preheating time of the balance, and the determination of the preheating time needs to be combined with the verification scale and the number of divisions of the balance. It can be concluded that, of course, the warm-up time will be slightly different due to the difference of the balance performance of each analytical balance manufacturer. However, in general, the balance needs to be warmed up for more than half an hour before verification. It should be noted that the warm-up time of the balance is also closely related to the accuracy. The higher the accuracy of the balance, the longer its warm-up time, so it must be operated in accordance with the instruction manual of the analytical balance, and the verification can be carried out after the warm-up time is reached.
(1) The balance should be placed on a firm and stable cement table or wooden table. The room must be clean and dry. At the same time, direct light should be avoided on the balance.
(2) When weighing, the material should be taken from the side door, and the door should be closed when reading to prevent air flow from causing the balance to swing.
(3) Volatile, corrosive, strong acid and strong alkali substances should be weighed in a weighing bottle with a lid to prevent corrosion of the balance.
(4)If the analytical balance is not used for a long time, it should be energized and preheated regularly, once a week, for 2 hours each time to ensure that the instrument is always in good use.
(5)The balance is preheated for 30 minutes before starting to weigh.
(6)Check the air bubbles in the balance at any time and pay attention to whether the balance is level.
(7)The balance should be regularly calibrated by a dedicated person to ensure the accuracy of the balance at any time.
(8)When weighing with a balance, handle it gently, and never allow greater impact and vibration on the balance, especially the weighing pan.
(9) Be careful not to spill materials in the balance when weighing.
(10) The action should be light when opening and closing the balance door, and sound is not allowed.