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平衡are often treated as the workhorses of the lab, but they are in fact extremely precise and sensitive measuring instruments. Their sophisticated components must be understood and handled properly to avoid inaccurate readings.

下面我们讨论了影响分析平衡准确性的许多因素。

Calibration

The first issue is as obvious as it is overlooked: calibration is essential to the integrity of your data. An ongoing servicing and calibration schedule, followed without fail for the life of the instrument, ensures the accuracy, reliability and repeatability of measurements.

The first issue is as obvious as it is overlooked: calibration is essential to the integrity of your data. An ongoing servicing and calibration schedule, followed without fail for the life of the instrument, ensures the accuracy, reliability and repeatability of measurements.

即使某些余额具有内部校准功能，许多实验室在具有经过认证的校准权重的新设备上进行了自己的校准测试，可帮助用户确定其特定实验室环境的校准设置。通常每年执行校准，但是如果使用余额大量使用平衡，则用户应考虑更频繁的测试，并在受振动或频繁温度或湿度波动的环境中使用。保持校准日期和程序的日志，包括引用NIST可追踪权重或其他设备。

Air Currents

气流会影响o的复杂机制f the analytical balance, just as temperature and vibration can alter the measurement of a small sample size. Changes in air pressure from ceiling fans, air conditioners, and open doors can compromise measurement accuracy. To counter the effects of air currents on laboratory balances, use a balance shield or place analytical balances within a balance enclosure (a “dead air” box). These enclosures also serve to protect the operator from noxious or toxic chemicals that are being weighed.

Temperature

The slightest change in room temperature can cause noticeable changes in the weight of the sample, so strict temperature controls help ensure accurate readings on the analytical balance. If the room temperature is too high, the sample can expand or lose some of its moisture due to evaporation. If the temperature falls too low, the sample could contract, or water may condense in the sample’s container. Both factors can affect measurement accuracy.

Vibration

冰箱，通风系统和其他设备的振动也损害了测量精度。由于样本量通常很小，因此最小的振动可以重新排列，位移或溢出样品，从而影响可用于测量的材料及其在平衡中的分布。较小的振动还会破坏分析平衡的精致机制，需要重新校准分析平衡。

考虑以下建议，以确保您的分析平衡获得最准确和最可重复的结果：

• Always check to be sure the balance is level.
• Close balance doors before weighing or place the balance within a "dead air" enclosure
• Equilibrate hot or cold samples to room temperature in closed containers prior to weighing.
• 保护吸湿样品免受水分的影响，直到称重之前。
• Place analytical balances in a protected environment away from temperature extremes such as direct sunlight, heating and AC vents.
• Avoid heavy traffic that causes vibrations in the weighing area
• Avoid overloading, which could cause damage to mechanical parts. This is especially important when microbalances are used