Correct Lab Balance Use for the Most Accurate Results
Cole-Parmer balances are designed to provide reliable results for many years, but if someone doesn’t understand balance best practices or forgets, then the balance may not give the most accurate weighing results, no matter how many features are on the balance. This rings true for any top-quality balance. There is a correct way to use a lab balance to get the most accurate results. The following details best practices before, during, and after balance use to enhance weighing skills and provide confidence in the accuracy of the weight result.
Before Use
Balance placement
Airflow
If adding a new balance for the first time, ensure the balance is positioned correctly in the laboratory or room. Determine where the airflow circulates in the room and place the balance away from drafty areas such as below air vents or near open doors. A draft shield is a useful tool to use on a balance to keep airflow away.
Environmental conditions
Consider the environmental conditions in the room. Is it hot or cold? Variables such as humidity, temperature, and air pressure can impact weighing accuracy. Use a temperature and humidity gauge to ensure the room has the optimal environment for weighing; check the user manual for recommended parameters. If unpacking a balance for the first time, it will need to sit in the room for several hours to reach room temperature before use. Plan accordingly.
Stability
Place the balance on a sturdy table or benchtop away from high-traffic areas such as hallways, elevators, meeting rooms, stairways, or doors. Even the slightest movement or vibration from a heavy foot may affect the accuracy. If this placement is not possible, an antivibration table should be considered for extra stability. An antivibration table is a solid-built table that decreases vibrations. It is always a good reminder not to lean on the table that holds the balance. This can cause instability to the table and balance.
Inspect for cleanliness
A clean balance is critical for weighing accuracy. Inspect and clean the balance before each use. A flannel cloth or soft brush is ideal for dusting and light cleaning. Use a non-abrasive cleaner to clean any light spills. Use a dry flannel cloth to clean glass parts (mild cleanser may be applied if it does not contain any abrasive substances). For heavier spills, refer to the balance manual for proper cleaning techniques. Certain cleaning agents may be required for specific substances. Set a maintenance schedule to deep clean the balance for optimal use and lifetime.
Level the balance
Once the balance is secure in its location and on the table, it needs to be leveled. Some balances have an automatic leveler. This would be the time to use that feature. If the balance does not have this feature, then it most likely has a bubble level and feet that can be adjusted. Adjust the feet of the balance until the bubble is centered, showing that the balance is in its correct position. Reconfirm the level results. If the balance is not level, critical weighing errors can occur, especially with precision weighing with analytical or micro balances.
Calibrate
Once a balance is level, it needs to be calibrated. Most electronic balances have internal and external calibration options such as the Cole-Parmer LA Analytical balance. Check the user manual on the best way to perform calibration. For Cole-Parmer balances, the user manual is located at coleparmer.com on the product page of the specific balance model number. If using a mechanical balance, make sure the scale is set to zero at the dial. Balances that are not properly calibrated will not weigh accurately regardless of the type of balance.
Tare
Set the balance to zero before weighing. If a container or pan is placed on the balance, the balance must be reset to zero, so the weight of that container is not included in the sample weight. It is best practice to place the sample in a weighing dish or pan and not directly onto the weighing platform.
During Use
Check temperatures of samples, tools, and hands
Temperature difference applies not only to the balance’s environment but also to the sample, the glassware, and anyone’s hands that are working with the balance. Hot and cold can affect the accuracy of the results, so samples, glassware or plasticware and hands need to be at the correct temperatures. Cool samples before using and place all samples in the center of the balance. Did you know that the miniscule weight of fingerprints, oils, lotions, and moisture can affect the weight on a balance? Use tweezers and gloves to add samples or items to the weighing platform. Many balances today have touchscreens that can be used while wearing gloves.
After Use
Leave the balance clean and ready for the next use or user
Leaving a clean balance will prepare it for the next use or user. It also limits cross-contamination and enhances lab safety, especially if a toxic substance was being weighed on the scale. If necessary, disassemble the balance per the manual and thoroughly clean.
Adhering to balance best practices can enhance weighing skills, provide the most accurate weights, and provide many years of reliable balance use.
Cole-Parmer balances are designed to provide reliable results for many years, but if someone doesn’t understand balance best practices or forgets, then the balance may not give the most accurate weighing results, no matter how many features are on the balance. This rings true for any top-quality balance. There is a correct way to use a lab balance to get the most accurate results. The following details best practices before, during, and after balance use to enhance weighing skills and provide confidence in the accuracy of the weight result.