Analytical Balances and Proper Weighing Practices

Electronic balances are susceptible to different environmental factors, and weighing errors can be generated by changes in the measuring device and the measured item, such as those caused by humidity, temperature, vibration, electromagnetic fields, barometric pressure, and light in the surrounding environment.

If you want to measure the weight of laboratory samples accurately, you need to have the correct scale. Learn how to operate a lab analysis balance to minimize measurement errors.

How to reduce the weighing error of analytical balance

Environmental impact:

Analytical balances are high-precision instruments and should be used with attention to the surrounding environment. It is recommended to use the balance in the following environment:

1. No vibration and strong noise

2. Try to be placed in an environment without air circulation; it should not be placed near doors and windows or in a windy environment.

3. Use the balance at a constant temperature and humidity (20±5°C) and not in direct sunlight.

Warm-up time:

Adequate preheating time can ensure the stability of the balance, such as insufficient preheating, which may lead to poor repeatability of samples, non-zeroing, and other problems. It is better to preheat the balance for one hour before use.

Weighing samples:

Weighing of oven-dried, volatile liquids or water-absorbent chemicals can cause problems with repeatability. Therefore, these samples need to be weighed with specialized weighing tools, such as liquid weighing flasks and weighing boats.

If the weighing sample is magnetic or electrostatic, it will affect the electromagnetic sensor and thus the value measured by the balance.

Calibration:

Electronic balances should be calibrated regularly from the first time they are used. Therefore, the laboratory must always have a set of certified standard weights. The calibration of the scale must be verified according to the requirements of a recognized national calibration laboratory. (Never touch the standard weights with your hands)

Proper handling of the sample

Gently place the sample in the center of the analytical balance pan. Use wooden tweezers or tweezers with rubber-coated tips to prevent scratching the sample.

Proper storage of weights

Always store weights in a room free from moisture, corrosive gases and dust. The counterweight's mass will increase if the weights are rusty or dust stuck to them. This will result in inaccurate readings.

After use, please place them in a desiccator to keep them dry.

Cleaning

The analytical balance's measurement accuracy and service life can be improved by routine cleaning.

When cleaning, switch off the power supply and unplug the power cord.

Ensure that no liquid or dust enters the housing of the analytical balance.

Applications of laboratory balances

Laboratory balances are used to measure the mass of objects, substances and chemicals. Laboratory balances have a variety of applications, including:

Research and development

Quality control

Production testing

Environmental testing

Pharmaceutical manufacturing

Food and Beverage Testing

Types of Lab Analytical Balances

Analytical Balance

This is the most widely used type of balance in the laboratory and it is accurate in its measurements. Typically analytical balances can measure objects with a mass of less than 0.001 grams. To ensure accuracy, analytical balances are usually placed in a temperature-controlled room and must be calibrated regularly.

Precision Balance

A precision balance is a type of balance used to weigh precise quantities. It is less sensitive to temperature changes and does not require frequent calibration. Precision balances are less accurate than analytical balances but are still suitable for many laboratory applications. They can usually measure masses of up to 500 grams.

Triple Beam Balance

Triple beam balances are the most common type of balance used in university science laboratories. They can measure objects with a mass of up to 26.50 grams.

Equal Arm Balances

Equal arm balances are used in high school and university science labs. They can measure objects with a mass of up to 500 grams (17.64 ounces).

Isometric balances are less sensitive to temperature changes than analytical and precision balances and do not require frequent calibration.

To ensure accuracy, equal arm balances should be checked periodically for levelness and recalibrated if they are moved to a new position.

Conclusion

By calibrating and maintaining laboratory analytical balances on a regular basis, errors can be minimised and the accuracy and reliability of experimental results can be ensured. It is only while maintaining the accuracy of the equipment that we can obtain reliable data and make the right decisions. Therefore, regular maintenance and calibration is crucial for laboratory analytical balances, which will help to improve the efficiency of laboratory work and ensure the accuracy of experimental results, thus promoting the smooth progress of scientific research and laboratory work.