How can you calibrate balances and scales for sample preparation?

1 Why calibrate balances and scales?

Calibration is the process of comparing the performance of a balance or scale with a known reference value, such as a certified mass standard. Calibration helps you to verify that your balance or scale is working correctly and within the specified tolerance limits. Calibration also helps you to identify and correct any errors or deviations that may affect the accuracy and precision of your measurements. By calibrating your balances and scales, you can improve the quality and reliability of your samples, avoid costly rework or errors, and comply with regulatory and quality standards.

3 How to calibrate balances and scales?

When calibrating balances and scales, there are various methods and standards to consider, depending on the type, model, and function of the balance or scale. Internal calibration is convenient and fast but may not account for external factors. External calibration is more accurate and reliable, but it can introduce human error or contamination. Traceable calibration is traceable to a national or international standard, such as the International System of Units (SI) or the National Institute of Standards and Technology (NIST), while accredited calibration is certified by an accredited laboratory or organization like the American Association for Laboratory Accreditation (A2LA) or the International Organization for Standardization (ISO). All of these methods are reliable, but they require more time and skill, and some may be more expensive and less accessible.

4 What are the best practices for calibrating balances and scales?

To ensure a successful and effective calibration of your balances and scales, there are some best practices to follow. First, you should select the appropriate method and standard for your balance or scale based on the manufacturer's specifications, accuracy and precision requirements, and the availability and affordability of the calibration service or equipment. Additionally, you need to choose the appropriate weight for your balance or scale, considering the capacity, readability, resolution of your balance or scale, and the mass range of your samples. This weight should be close to the nominal value of your balance or scale and within the tolerance limits of your accuracy and precision requirements. Additionally, you should select an appropriate location for your balance or scale away from sources of vibration, heat, cold, humidity, air currents, dust, or electromagnetic interference. This location should be stable, level, and clean with a constant temperature and humidity within the manufacturer's specifications. Furthermore, you should choose an appropriate time for your calibration; preferably before or after normal working hours when environmental conditions are more stable with less traffic or activity in the laboratory. Lastly, you should follow the manufacturer's instructions and procedures for your calibration using correct tools and techniques while recording results and any adjustments or corrections. The calibration should be done in a consistent manner with the same weight, position, and sequence each time.

6 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?