Analytical

What are Analytical Balances?

An analytical  balance is a highly sensitive laboratory instrument which accurately measure mass in the sub-milligram range  to a high degree of precision . Analytical Balances have a weighing capacity in the range of 100-500 g and a readability of 0.1 mg – 0.001 mg.

Analytical balances have a draft shield or weighing chamber in the form of a transparent enclosure so that air currents and dust do not affect the Analytical Balances Operation. Analytical balances should only be used by trained personnel.

An Analytical Balance differs from a precision balance in terms of readability. An Analytical Balances has a have a higher readability (0.0001g)  versus a precision balance (0.001g) and as a result tends to be more expensive.

Analytical Balance Applications include;

• Sample Preparation
• Formulation
• Interval Weighing
• Routine Pipette Testing
• Differential Weighing
• Density Analysis

What industries are Laboratory Balances used in?

Laboratory Balances are utilised across a large variety of industries.  They are commonly used in laboratories due to the level of precision required in scientific experiments. In the laboratory, Analytical Balances can be used for weighing medicine, chemicals and other hazardous compounds, density determination and pipette calibration. An Analytical Balance can also be used in Universities or by veterinarians for measuring compounds.

Where should I keep my Laboratory Balance?

A Laboratory Balance detects very fine increments and so should be kept in a separate interior room where there are few disturbances as small vibrations, temperature fluctuations,  breezes, spills and general foot traffic , as these can all skew results. An analytical balance benefits from low-impact environments. Anti-vibration tables and anti-static mats may be used to ensure weighing accuracy. Analytical balances must be carefully maintained and regularly calibrated.

How do I use an Analytical Balance?

• Ensure your analytical balance meets all FDA, CFR and other standards, this can be cross-checked in the Analytical Balances manual
• Ensure calibration has been carried out on the analytical scales before putting it into operation, check what the calibration procedure and frequency is the analytical balances henceforth.
• Place the analytical balance in a quiet, draft free room on a sturdy table so there are few vibrations. Bear in mind that when moved, the analytical balance will need to be relocated so choose carefully where to place it.
• Plug in the analytical balance and wait for it to go through its internal checks. Wait for the display to indicate zero weight
• After opening the door of the analytical balance, place the substance on the middle of the pan in using tweezers, tongs or gloves (fingerprints add mass). The substance should be placed on pre-weighed weighing paper.
• Keep adding substance until the desired weight is reached, then shut the door and wait for the reading to stabilise.
• When finished, switch the analytical balance to standby mode and clean the inside using a soft brush.

Factors affecting Laboratory Balances

As Analytical Balances are so precise (up to four decimal places), they are very sensitive to external disturbances in the environment and also by the way they are installed and handled. This affects the readability of the lab balance and could potentially give inaccurate results.  

• CALIBRATION – Calibration is the best way to test the accuracy of balances. It ensures ongoing integrity of results, repeatability and accuracy.

• TEMPERATURE – Temperature fluctuations for both environment and weighing equipment can lead to changes in laboratory balances readings and so temperature around analytical balances must be strictly regulated. A rise in temperature may lead to water evaporating off the product or the product expanding. Temperatures that are too low, may cause condensation or cause the product to contract. All of these will lead to an inaccurate reading. Weighing instruments should not be turned off so temperature remains consistent and room temperature should constantly be maintained to not fluctuate more than 2 degrees.

• VIBRATIONS – Vibrations can include general footfall and doors/cupboards banging, as well as more subtle vibrations such as those from refrigerators and ventilation systems. Due to the small size of the samples, these disturbances can cause spills or displace the material which can inhibit sample availability as well as sample distribution. Re-calibration of your analytical balance may be required if these issues occur which will mean lost time and increased costs.

• CHEMICALS – Volatile samples can be sensitive to atmospheric changes which can lead to chemical reactions which changes the sample state. It is important to ensure that the sample remains chemically inert.

• AIR CURRENTS – Air currents can come from opening and closing doors, air conditioning or ceiling fans. As Analytical Balances are so sensitive, this can affect measurements.

• USER ERRORS – Improper calibration or leaving samples exposed can lead to laboratory balances obtaining inaccurate results. Labs usually enforce strict standard operating procedures in order to mitigate this risk.

• HUMIDITY– Humidity levels in labs are usually below 20% with 24-hour air conditioning. This leads to a dry environment which can cause friction, which can then cause static electricity.  static electricity can cause considerable errors and discrepancies in weighing measurements. This can be managed by adjusting humidity levels to 40% when the analytical balances are being installed. Anti-static flooring should be used and plastic containers should not be used to store the sample as the can be porous.

Can we help you with your Analytical lab balance?

To find out how we can help you with your analytical laboratory balance requirements, simply contact us today. We look forward to being of assistance.

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