1. What is Percentage Uncertainty?

Percentage uncertainty (or relative uncertainty) expresses the absolute uncertainty as a percentage of the measured value. It provides a standardized way to compare the precision of measurements of different magnitudes.

2. How Does the Calculator Work?

The calculator uses the percentage uncertainty formula:

Where:

• Absolute Uncertainty — The uncertainty in the same units as the measurement
• Measured Value — The actual measurement value

Explanation: The formula shows what fraction of the measured value the uncertainty represents, converted to a percentage.

3. Importance of Uncertainty Calculation

Details: Percentage uncertainty is crucial in scientific measurements as it allows comparison of precision across different scales and units. It helps determine the reliability of measurements and experimental results.

4. Using the Calculator

Tips: Enter both absolute uncertainty and measured value in the same units. The measured value must be greater than zero. The calculator will output the percentage uncertainty.

5. Frequently Asked Questions (FAQ)

Q1: What's the difference between absolute and percentage uncertainty?
A: Absolute uncertainty has the same units as the measurement, while percentage uncertainty is dimensionless and allows comparison across different measurements.

Q2: What is a good percentage uncertainty value?
A: This depends on the field, but generally <5% is acceptable for most applications, <1% is good, and <0.1% is excellent.

Q3: Can percentage uncertainty be greater than 100%?
A: Yes, this occurs when the absolute uncertainty is larger than the measured value, indicating very low precision.

Q4: How is this different from percentage error?
A: Percentage error compares to a known reference value, while percentage uncertainty relates to measurement precision regardless of accuracy.

Q5: When should I use percentage uncertainty?
A: Use it when you need to compare the precision of different measurements or when combining uncertainties in calculations.