虽然很长但这部分太实用，建议针对自己家的具体情况升级一下你的 称量操作规程，啥你还没有？
OPERATION OF THE ANALYTICAL BALANCE 分析天平的操作
Select the appropriate balance for the quantity and performance needed. General chapter 41 provides requirements for balances used for materials that must be accurately weighed. The balance user should check the balance environment (vibration, air currents, and cleanliness) and status of calibration before use.
应根据所需的质量和性能去选择适当的天平。通则<41>规定了必须精确称量的材料用的天平的要求。天平使用者在使用前应检查天平环境(振动、气流、清洁度)和校准状态。
Receivers容器
To ensure suitable performance in measuring the weight of a specimen, analysts should consider selection of a proper receiver for the material.
为了确保测量样品重量时的适当性能，分析人员应考虑为材料选择合适的容器。
GENERAL CHARACTERISTICS容器的通用特性
All receivers must be clean, dry, and inert. The total weight of the receiver plus the specimen must not exceed the maximum capacity of the balance. With a properly maintained and adjusted laboratory balance, weighing uncertainty for small samples, i.e., net weights with a mass not exceeding typically a few percent of the capacity of the balance, essentially is determined by the repeatability. However, repeatability depends on the size and surface area of the weighed object. For this reason large or heavy receivers introduce a deviation from the conditions under which the repeatability was determined without considering the receivers. Therefore, either receivers of a low mass and small surface should be used (especially in cases when specimens of low weight are being measured) or the repeatability test should be performed with the receiver placed on the weighing pan as a preload. Receivers should be constructed from nonmagnetic materials in order to prevent magnetic interference with electronic balance components. Receivers should be used at ambient temperature in order to prevent the formation of air currents within the weighing chamber.
所有的容器必须是干净、干燥和惰性的。容器加上试样的总重量不得超过天平的最大容量。在适当维护和调整的实验室天平中，小样本的称重不确定度，即质量不超过天平容量的几个百分点的净重，基本上是由重复性决定的。然而，可重复性取决于被称重物体的大小和表面积。由于这个原因，大的或重的容器引入了与在没有考虑容器的情况下确定的重复性条件的偏差。因此，要么使用质量小、表面小的容器(特别是测量重量低的样品时)，要么将容器放置在称量盘上作为预载荷进行重复性试验。为了防止电子天平组件受到磁干扰，容器应该由非磁性材料构成。容器应在环境温度下使用，以防止在称重室内形成气流。
SOLID SAMPLES固体样品
Receivers for weighing solid materials include weighing paper, weighing dishes, weighing funnels, or enclosed vessels, including bottles, vials, and flasks. Hygroscopic papers are not recommended for weighing because they may have a detrimental effect on the observed results.
称量固体材料的容器包括称量纸、称量盘子、称量漏斗或封闭容器，包括瓶子、小瓶和烧瓶。不建议用吸湿纸称量，因为它们可能对观察结果有不利影响。
Weighing dishes typically are constructed from a polymer or from aluminum. Antistatic weighing dishes are available for measuring materials that retain static electricity. Weighing funnels typically are constructed from glass or from a polymer. The design of this type of receiver combines attributes of a weighing dish and a transfer funnel, which can simplify the analytical transfer of a weighed powder to a narrow-necked vessel such as a volumetric flask. For solid samples that are volatile or deliquescent, analysts must weigh the material into an enclosed vessel. Where practical, analysts should use an enclosed vessel with a small opening in order to reduce sample weight loss from volatilization or weight gain from the adsorption and absorption of atmospheric water.
称重碟通常由聚合物或铝制成。防静电称量盘可用于测量保留静电的材料。称重漏斗通常由玻璃或聚合物构成。这种类型的容器的设计结合了称重盘和转移漏斗的特点，可以简化将称重后的粉末转移到窄颈容器(如容量瓶)的分析过程。对于易挥发或潮解的固体样品，分析人员必须将材料称重放入一个封闭的容器中。在实际情况下，分析人员应使用一个有小开口的封闭容器，以减少样品挥发造成的重量损失或因吸附和吸收环境水汽而增加的重量。
LIQUID SAMPLES液体样品
Receivers for liquid samples typically are inert, enclosed vessels. For liquid samples that are volatile or deliquescent, analysts should use an enclosed vessel with a small opening, and the enclosure should be replaced rapidly following material transfer. Special precautions should be taken to be certain that the receiver and the enclosure are constructed from a material that is compatible with the liquid sample. The receiver and enclosure must have a seal that is sufficient to prevent leaks from a liquid that is of low viscosity or has low surface tension or a low boiling point.
液体样品的接收器通常是惰性的、封闭的容器。对于易挥发或易潮解的液体样品，分析人员应使用具有小开口的封闭容器，并在材料转移后迅速更换外壳。应采取特别的预防措施，以确保容器器和外壳由与液体样品兼容的材料构成。容器和外壳必须有足够的密封，以防止低粘度或具有低表面张力或低沸点的液体泄漏。
Types of Weighing称量类型
WEIGHING FOR QUANTITATIVE ANALYSIS定量分析的称量
The initial step for many quantitative analyses is to accurately weigh a specified amount of a sample. General Notices,
6.50.20 Solutions stipulates that solutions for quantitative measures must be prepared using accurately weighed analytes: i.e., analysts must use a balance that meets the criteria in 41. Errors introduced during the weighing of a sample can affect the accuracy of all subsequent analytical measurements.
许多定量分析的第一步是准确地称出指定量的样品。凡例6.50.20 溶液应确保定量测量的溶液必须使用精确称重的分析物制备:
也就是说,分析师必须使用符合<41>;标准的天平。样品称重过程中引入的误差会影响所有后续分析测量的准确性。
ADDITION WEIGHING增量法
Addition weighings typically are used for solid samples or liquid samples for which volatility is not an issue. The receiver is placed on the balance. After the balance display stabilizes, the analyst should tare the balance; add the desired amount of material to the receiver; allow the balance display to stabilize; record the weight; and quantitatively transfer the material to an appropriate vessel or, if it cannot be guaranteed that the entire amount has been transferred, weigh the receiver again and note the weight difference.
增量法通常用于固体样品或液体样品，样品不应存在挥发性的问题。将容器放在天平上。天平显示稳定后，分析员应检查天平;将所需量的物料加入容器;允许天平显示稳定;记录重量;并定量转移物料到适当的容器，或，如果不能保证全部数量已转移，再次称重容器，并注意重量的差异。
DISPENSE WEIGHING减重法（配重法）
Dispense weighing typically is used for weighing emulsions or viscous liquids such as ointments. In these situations it is not practical to weigh the material into a typical receiver. Accordingly, the analyst should tare the balance; place the sample on the balance in a suitable container (e.g., a bottle, tube, transfer pipet, or syringe) that has been wiped clean on the outside; record the weight after the balance display stabilizes; transfer the desired amount of sample to an appropriate receiving vessel, such as a volumetric flask; and place the pipet or syringe back onto the balance. The difference in the two weighings is equal to the weight of the transferred specimen.
减重法通常用于乳剂或粘稠液体如软膏的称量。在这些情况下，将材料称重放入典型的容器是不实际的。因此，分析师应该权衡利弊;将样品置于适当的容器中(例如，瓶、管、移液管或注射器)，并将其外部擦拭干净;天平显示稳定后记录重量;将所需数量的样品转移到适当的接收容器中，如容量瓶;然后把移液管或注射器放回天平上。两种称重法之差等于转移试样的重量。
GRAVIMETRIC DOSING定量计重
Gravimetric dosing typically is used for sample and standard preparations or capsule filling. For such weighing the analyst places the volumetric flask, vial, or capsule shell on the balance; tares the balance after the balance display stabilizes; adds the solid or liquid components into the receiver by means of dosing units; and records the respective weights.
定量计重通常用于样品和标准制剂或胶囊填充。为了称重，分析人员将量瓶、小瓶或胶囊壳放在天平上;在天平显示稳定后“去皮”; 通过以剂量单位将固体或液体成分添加到上述容器中;并记录各自的重量。
Problem Samples 问题样品
ELECTRICALLY CHARGED SAMPLES AND RECEIVERS带电的样品和容器
Dry, finely divided powders may be charged with static electricity that can make the powder either attracted to or repelled by the receiver or the balance, causing inaccurate weight measurements and specimen loss during transfer. A drift in the balance readings should alert the operator to the possibility that the material has a static charge. Commercially available balances with a built-in antistatic device can be used to remedy the problem. Such devices may use piezoelectric components or a very small amount of a radioactive element (typically polonium) to generate a stream of ions that dissipate the static charge when passed over the powder being weighed. Antistatic weigh boats, antistatic guns, and antistatic screens also are commercially available. The static charge depends also on the relative humidity of the laboratory, which in turn depends on atmospheric conditions. Under certain conditions, static charge is caused by the type of clothing worn by the operator and this charge can cause large errors in the weighing. Borosilicate glassware and plastic receivers have a well-known propensity for picking up static charge, especially at low relative humidity. The gloves used to protect the operator also may increase the potential for a static charge problem. Placing the container in a metal holder may help to shield the static charge, and antistatic gloves also can help to alleviate the problem.
干燥的、细碎的粉末可能带电，静电可以使粉末吸引或排斥容器或天平，造成不准确的重量测量和样品在传输过程中的损失。若天平读数的漂移，可能提示操作者注意材料具有静电荷的可能性。市售的带有内置防静电装置的天平可以用来解决这个问题。这种装置可以使用压电元件或极少量的放射性元素(通常是钋)来产生离子流，当离子流经过被称重的粉末时，会驱散静电电荷。抗静电称重舟、抗静电枪和抗静电屏幕也可在市售获得。静电荷还取决于实验室的相对湿度，而相对湿度又取决于大气条件。在一定条件下，静电电荷是由操作人员所穿的衣服类型引起的，这种静电电荷会造成称重时的较大误差。硼硅玻璃器皿和塑料容器有一个众所周知的富集静电电荷倾向，特别是在低相对湿度。用于保护操作员的手套也可能增加静电问题的可能性。将容器放置在金属支架中可以帮助屏蔽静电，防静电手套也可以帮助缓解这个问题。
VOLATILE SAMPLES挥发性样品
When weighing a liquid that has a low boiling point, analysts must receive the specimen in a vessel with a gas-tight enclosure of small diameter. The analyst then tares the vessel and enclosure, adds the desired amount of sample, and replaces the enclosure. After the balance display stabilizes, the analyst records the specimen weight.
当称量沸点低的液体时，分析人员必须将样品放入一个小直径的气密容器中。然后，分析人员去皮容器和外壳，添加所需数量的样品，并更换外壳。天平显示稳定后，分析人员记录样品重量。
WARM OR COOL SAMPLES 冷或热的样品
Samples that are warm or cool should be equilibrated in the laboratory, or the weight readings may be erroneous. With regard to warm samples, the apparent weight is smaller than the true weight because of heat convection. For example, a flask that is warmer than ambient air warms up this air, which then flows upward along the flask and reduces the apparent weight of the contents by viscous friction.
热的或冷的样品应该在实验室中保持平衡，否则重量读数可能会出错。对于热样品，由于热对流的影响，表观重量小于真实重量。例如，一个比周围空气温度高的烧瓶会使空气升温，然后空气沿着烧瓶向上流动，并通过粘性摩擦降低内容物的表观重量。
HYGROSCOPIC SAMPLES 引湿性样品
Hygroscopic materials readily absorb moisture from the atmosphere and steadily gain weight if left exposed. Therefore, hygroscopic samples must be either weighed promptly or placed in a vessel with a gas-tight enclosure. For a gas-tight vessel, analysts should tare the vessel and enclosure, add the desired amount of sample, and replace the enclosure. After the balance display stabilizes, the analyst can record the specimen weight.
吸湿材料很容易从大气中吸收水分，如果暴露在外面，就会稳定地增加重量。因此，吸湿样品必须立即称重或放置在气密容器中。对于气密容器，分析人员应去皮容器和外壳，添加所需数量的样品，并更换外壳。天平显示稳定后，分析人员可以记录样品重量。
ASEPTIC OR BIOHAZARDOUS SAMPLES无菌或有生物危害的样品
The weighing of sterile or biohazardous samples should take place within the confines of a clean bench, biosafety cabinet, isolator, or similar containment device. Air flow within the hood potentially can cause balance instability, so after a balance has been installed under a hood, analysts should perform a rigorous qualification study with suitable weight artifacts (see 41) in order to determine the acceptability of the balance performance in this environment.
无菌或有害生物样本的称重应在洁净工作台、生物安全柜、隔离器或类似的密封装置的范围内进行。保护罩内的气流可能会导致平衡不稳定，因此，在将天平安装在保护罩下之后，分析人员应该使用合适的砝码工件进行严格的鉴定研究(参见41)，以确定天平在此环境中的性能可接受性。
WEIGHING CORROSIVE MATERIALS重腐蚀材料
Many chemicals, such as salts, are corrosive, and materials of this nature should not be spilled on the balance pan or inside the balance housing. Extra care is essential when materials of this nature are weighed. Analysts should consider the use of sealed containers such as weighing bottles or syringes. In the event of a spill, requalification of balance may be necessary, depending on the nature of the spill.
许多化学物质，如盐，具有腐蚀性，这种性质的物质不应泄漏在天平盘或壳内。对这种性质的材料进行称重时，格外小心是必要的。分析人员应考虑使用密封容器，如称重瓶或称量勺。一旦发生泄漏，根据泄漏的性质，可能需要重新确认天平。
Safety Considerations When Weighing称重时的安全注意事项
During a weighing, the analyst may be exposed to high concentrations of a pure substance. The analyst must carefully consider this possibility at all times and should be familiar with the precautions described in the substance′s Material Safety Data Sheet before weighing it. Hazardous materials should be handled in an enclosure that has appropriate air filtration. Many toxic—and possibly allergenic—substances present as liquids or finely divided particles. When weighing these substances, analysts should use a mask that covers the nose and mouth to prevent any inhalation of the substance, and they should use gloves to prevent any contact with the skin. [NOTE—The use of gloves is good practice for handling any chemical. If it is necessary to handle the container being weighed, the analyst should wear gloves not only for self-protection but also to prevent moisture and oils from being deposited on the weighed container.]
在称重过程中，分析人员可能会暴露在高浓度的纯物质中。在称量之前，分析人员必须始终仔细考虑这种可能性，并应熟悉该物质的《物质安全数据表》中所述的预防措施。有害物质应该在具有适当空气过滤的保护中处理。许多有毒物质——可能是致敏物质——以液体或细颗粒的形式存在。在称量这些物质时，分析人员应使用面罩遮住口鼻，以防止任何物质的吸入，并应使用手套，以防止与皮肤接触。【注意:手套是处理任何化学品的好方法。如果需要处理被称量的容器，分析人员应该戴手套，这不仅是为了自我保护，也是为了防止水分和油沉积在称量的容器上。】
