Which of the following must be performed before using the analytical balance?

• A. Cleaning The Balance And Removing Sample Residues.
• B. Determine The Sensitivity Of The Balance Using Calibration Weight.
• C. Checking The Level Of The Balance By Adjusting The Air Bubble.
• D. All Of The Above.

Answer: (D)

Before using an analytical balance, you must ensure it is properly prepared to guarantee accurate measurements. Cleaning the balance and removing sample residues is essential because any leftover material or contamination adds mass that isn’t from the new sample, skewing the result. Leveling the balance is also crucial; when the balance isn’t perfectly horizontal, readings can drift or tilt, leading to systematic errors. Checking or determining the balance’s sensitivity with calibration weights verifies that the instrument reads true values across its range, ensuring the displayed mass corresponds to the actual mass.

Together, these steps address cleanliness, mechanical alignment, and accuracy verification, so performing all of them is the best practice before taking measurements.