Uncertainty Calculator

Step-by-Step Guide to Using the Uncertainty Calculator

Introduction

The Uncertainty Calculator is designed to help you calculate both absolute and percentage uncertainties, as well as confidence intervals, for measured values. Follow these steps carefully to get accurate results.

Step 1: Enter the Measured Value

Begin by locating the field labeled Measured Value. Enter the value you have measured into this field. This should be a numerical input within the range of -1,000,000 to 1,000,000. Ensure this value is entered correctly, as it forms the basis of further calculations.

Step 2: Select the Type of Uncertainty

Next, move to the dropdown menu labeled Type of Uncertainty. You have two options here:

• Absolute Uncertainty
• Percentage Uncertainty

Select the type of uncertainty that applies to your measurement.

Step 3: Enter the Uncertainty Value

Proceed to the field labeled Uncertainty Value. Enter the uncertainty associated with your measurement. Ensure it is a non-negative number ranging from 0 to 1,000,000.

Step 4: Choose the Confidence Level

Select the Confidence Level from the available options. The confidence level options along with their corresponding Z-scores are:

• 90% Confidence (Z-score: 1.645)
• 95% Confidence (Z-score: 1.960)
• 99% Confidence (Z-score: 2.576)

Pick the confidence level that is appropriate for your analysis.

Step 5: Review Calculated Results

Once all input fields are correctly filled, the following results will be automatically calculated and displayed:

• Absolute Uncertainty: If Absolute Uncertainty is selected, this is simply the entered Uncertainty Value. If Percentage Uncertainty is selected, it is calculated as the measured value multiplied by the uncertainty value divided by 100.
• Percentage Uncertainty: Conversely, for Percentage Uncertainty selection, this is the directly entered Uncertainty Value. If Absolute Uncertainty is selected, it is calculated as (uncertainty value / measured value) times 100.
• Confidence Interval: Product of the absolute uncertainty and the selected confidence level.
• Lower Bound: Calculated as the measured value minus the confidence interval.
• Upper Bound: Calculated as the measured value plus the confidence interval.
• Relative Error: Computed as the absolute uncertainty divided by the absolute value of the measured value, given in percentage.

Step 6: Evaluate and Interpret Results

With these results, you can now analyze the reliability and range within which the true value lies considering the level of confidence and type of uncertainty chosen. Adjust your interpretation based on the specific context of your measurement and application needs.