Thank you, and to clarify i mean 25 cent quarters.Rx7man said:If the scale has the capacity to weigh all parts together, I'm quite certain you'd have better accuracy.
Most scales are ±1 on the least significant digit (in some cases ±5 which sounds like yours), and ± x% total error.. by weighing all parts together you reduce the cumulative error on the significant digit part, though the percentage error would remain the same... The smaller your pieces are, the more accurate you'll be by weighing them all together.
For example.. if the real weight is.0010g for each piece it means the scale could show between .0005 and .0015g grams... weighing each piece individually means you only know the total weight will be between .0025 and .0075g.
Weighing them together you will get .005g ± .0005gBut how are you getting 5 quarters?
Hi brycenrg:brycenrg said:So i could just say (x ± .0005g) + (c ± .0005g)+ (a ± .0005g)+ (z ± .0005g)+ (d ± .0005g) = (x1+x2+x3+x4+x5) ± .0025
Thank you buzzBuzz Bloom said:Hi brycenrg:
Your answer that measuring all five at the same time is better than measuring one at a time is correct. However, what the ± .0005g means is that the .0005g is the standard deviation of the scale's error distribution. To get the standard deviation from adding the five separate measurements, you have to calculate the square root of the sum of the squares. Thus the standard deviation is
√(5 × .00052) g = .0005 × √5 g. Thus the answer from 5 separate weighings is
(x1+x2+x3+x4+x5) ± .0005 × √5 g ≈ (x1+x2+x3+x4+x5) ± .0011 g.
Regards,
Buzz
Uncertainty in measurement refers to the potential error or variability in a measurement result. It is the degree of doubt or lack of confidence in the accuracy of a measured value.
There are several factors that can contribute to uncertainty in measurement, including the precision and accuracy of the measuring instrument, human error, environmental conditions, and limitations of the measurement process.
Uncertainty in measurement is typically expressed as a range of values, known as the measurement uncertainty interval, which represents the potential error in a measurement result. It is often expressed as a percentage or a specific value with units.
Uncertainty in measurement can be reduced by using more precise and accurate measuring instruments, minimizing human error through proper training and techniques, and controlling environmental conditions during the measurement process. Repetition of measurements and statistical analysis can also help reduce uncertainty.
It is important to consider uncertainty in measurement because it provides a measure of the reliability and accuracy of a measurement result. Without accounting for uncertainty, it is impossible to determine the true value of a measured quantity and make informed decisions based on the data.