What are at least 3 possible sources of error in using the triple balance beam. How might errors be minimized?

Precision instrument Triple Beam Balance will give close to the same measurement of a sample over and over. However, there some errors that can occur which will ultimately lead to getting inaccurate results.

Non-calibrated (or poorly calibrated) Triple Beam Balance can give the same incorrect readings over and over.


Take as many trials as possible—the more trials you do, the less likely one odd result will impact your overall lab results

With the pan empty, move the three sliders on the three beams to their leftmost positions, so that the balance reads zero. If the indicator on the far right is not aligned with the fixed mark, then calibrate the balance by turning the set screw on the left under the pan.

Parallax error in reading the scales.

An error which arises in the reading of the scale is introduced by the positionong of the eyes - an effect known as parallax. Looking from the side will give an improper reading.


Avoid parallax error with proper eye alignment - a direct line of sight toward the scale. Uncertainty due to this effect can be reduced by making sure that your eye is at 90 degrees to the scale when you take the measurement.

Misreading the scale.

Most equipment has metric values. It is easy to mistakenly read metric values.


Read the numbers and graduations carefully on a tape measure, to make sure that you're taking off the correct measurement from the correct section of the scale. Avoid interruptions before writing down the result.

For more info about getting the most accurate readings using a Triple Beam Balance, see links below:




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