Weighing Using An Analytical Balance
TLDRThis script offers a detailed guide on using analytical balances, emphasizing their proper care and calibration. It introduces two weighing methods: 'weighing by addition' for single samples and 'weighing by difference with tare' for multiple samples. The process includes cleaning, leveling, and equilibrating the balance, as well as accurately recording the mass of samples. The script ensures users understand the importance of precision and cleanliness in laboratory weighing.
Takeaways
- 🔬 Analytical balances are sophisticated measuring devices that require proper use and care as per manufacturer's recommendations.
- 🏗️ Balances should be placed in a permanent, undisturbed location on a firm surface to avoid interference from drafts, vibrations, or other lab activities.
- 🧼 Balances must be kept clean at all times, with immediate cleaning of any spills to ensure accuracy.
- 📅 Regular checks are necessary, either daily or weekly, using a calibration weight in accordance with specific quality control requirements.
- 📊 Analytical balances are typically inspected annually to maintain their precision and reliability.
- 📦 Weighing by addition involves placing an empty container on the balance, zeroing it, and then adding the sample to reach the desired mass.
- 🔄 Before using the balance, ensure it is clean and level, and avoid touching the balance with bare hands to prevent contamination.
- 📈 The mass indicated on the balance readout after equilibration is the actual mass added to the container.
- 🔄 Weighing by difference with tear involves starting with a bulk sample, removing the required sample, and recording the negative value displayed on the balance.
- 📝 Record the mass of each sample once the required mass is obtained to maintain an accurate record for further analysis.
- 🛑 After all samples are obtained, ensure the balance is cleaned and turned off to preserve its condition for future use.
Q & A
What are analytical balances and why are they important in a laboratory setting?
-Analytical balances are sophisticated measuring devices used in laboratories for precise weight measurements. They are important because they ensure accuracy in experiments and chemical analyses, which are critical for reliable scientific results.
How should analytical balances be placed in a laboratory?
-Analytical balances should be placed in a permanent location on a firm surface where they will not be disturbed by drafts, vibrations, or other laboratory activities.
Why is it necessary to keep analytical balances clean?
-Analytical balances must be kept clean at all times to prevent contamination that could affect the accuracy of measurements. Spills should be cleaned immediately to maintain this cleanliness.
What is the purpose of checking analytical balances with a calibration weight?
-Checking analytical balances with a calibration weight ensures that they are accurate and functioning properly. This is done either daily or weekly according to specific quality control requirements.
How often are analytical balances typically inspected?
-Typically, analytical balances are inspected annually to ensure their continued accuracy and reliability in weighing.
What is the weighing by addition method and when is it used?
-Weighing by addition is a method where the empty receiving vessel is set to zero on the balance, and a bulk sample is added to reach the required mass. This technique is useful when single samples are required.
What steps should be taken before using an analytical balance for weighing by addition?
-Before using an analytical balance for weighing by addition, ensure that the balance is clean and level, turn it on, press the tare bar to get a stable zero reading, and use a clean, dry weighing container.
What is the process of adding the substance to be weighed using the weighing by addition method?
-The process involves placing a clean weighing container on the balance, pressing the tare bar, removing the container, adding the substance with a spatula or scoopula, replacing the container on the balance, and allowing the balance to equilibrate before reading the mass.
What is the weighing by difference method and when is it used?
-Weighing by difference is a method used when several duplicate masses of a material need to be weighed out. The bulk sample mass is set to zero, and the required sample is removed, resulting in a negative value on the balance.
How should the weighing by difference method be performed?
-To perform weighing by difference, place a clean, dry weighing bottle on the balance, press the tare to reset to 0 G, remove some sample, transfer it to a receiving vessel, return the bottle to the balance, and equilibrate before reading the negative value, which is the actual mass placed into the vessel.
What should be done after obtaining all required samples using an analytical balance?
-After obtaining all required samples, ensure that the balance is clean and turned off to maintain its accuracy and prevent any damage.
Outlines
🔍 Proper Use and Maintenance of Analytical Balances
This paragraph discusses the importance of using and maintaining analytical balances as per manufacturer's instructions. It emphasizes the need for a stable location free from disturbances, cleanliness, and immediate cleaning of spills. The paragraph also explains the calibration process, which can be daily or weekly, and the annual inspection of balances. It introduces two weighing methods: 'weighing by addition' and 'weighing by difference with tear', detailing the steps involved in each method, including ensuring the balance is clean and level, using a tear bar for zeroing, and recording the mass accurately. The focus is on the precision required in laboratory weighing tasks.
Mindmap
Keywords
💡Analytical Balances
💡Calibration Weight
💡Weighing by Addition
💡Tear Bar
💡Weighing by Difference
💡Spills
💡Quality Control
💡Level
💡Stable Zero Reading
💡Weighing Container
💡Equilibrate
Highlights
Analytical balances are sophisticated devices requiring careful use and maintenance as per manufacturer's recommendations.
Balances should be placed in a permanent location on a firm surface away from disturbances.
It is crucial to keep balances clean at all times and address spills immediately.
Balances must be checked regularly with calibration weights for quality control.
Annual inspections of analytical balances are typically conducted for accurate weighing.
Weighing by addition is a method used for obtaining single samples to a required mass.
Ensure the balance is clean and level before use for accurate weighing.
Use a clean, dry weighing container to avoid contamination.
The process of equilibration is necessary for the balance to provide an accurate reading.
Weighing by difference with tear is suitable for weighing out several duplicate masses.
A bulk sample mass is teared, and the required sample is removed for duplicate weighing.
The negative value on the balance indicates the actual mass placed into the receiving vessel.
Use a spatula to remove a sample and transfer it to a clean, dry weighing bottle with a lid.
Ensure the balance is clean and turned off after use to maintain its accuracy.
Proper handling and care of analytical balances are essential for reliable measurements.
Regular calibration and inspection are key to maintaining the performance of analytical balances.
The transcript provides a detailed guide on the use and maintenance of analytical balances for laboratory settings.
Transcripts
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