Uncertia: Measurement Budget

GUM-Style Budgets, Offline

$0.99 · Designed for iPad. Not verified for macOS.

New in 2.0: Student-t coverage factors, Type A from raw readings, correlated inputs, a Monte Carlo check, guard-banded pass/fail, and PDF/CSV reports. One purchase. Uncertia builds measurement uncertainty budgets the way the GUM (JCGM 100:2008) describes them, on your iPhone or iPad, with every step visible. It is made for calibration technicians, metrologists, quality engineers, laboratories working to ISO/IEC 17025, and students learning uncertainty evaluation. BUILD THE BUDGET - Keep any number of budgets in a local library; duplicate one to start the next - Type A rows from raw readings: paste or type them and get the mean, experimental standard deviation s, s/√n, and ν = n − 1 - Type B rows from certificates and specifications: normal (k = 2 or the certificate's k), rectangular, triangular, U-shaped, or a standard uncertainty you already have - Sensitivity coefficients, input estimates, units, and evidence notes for every row - Degrees of freedom per row, typed directly or estimated from how reliable a bound is - Correlation coefficients between rows, with a check that the set is consistent SEE THE RESULT - Combined standard uncertainty, including correlation terms - Welch–Satterthwaite effective degrees of freedom - Coverage factor from the Student t distribution at 68.27, 90, 95, 95.45, 99, or 99.73 %, or a fixed k - Expanded uncertainty reported with two significant digits and the result rounded to match - Contribution chart showing which source dominates the variance CHECK IT - Monte Carlo propagation of the input distributions (JCGM 101) with up to one million trials, a histogram, and a comparison of the coverage interval with y ± U - Conformity decisions against tolerance limits with simple acceptance or a guard band of U (ILAC-G8), probability of conformity, and test uncertainty ratio REPORT IT - PDF report with the statement, budget table, evidence, coverage reasoning, Monte Carlo check, conformity decision, and your notes - CSV table for spreadsheets and quality systems - Backup and restore files for the whole library LEARN IT - A written method guide covering Type A and Type B evaluation, distributions, sensitivity coefficients, correlation, effective degrees of freedom, coverage factors, Monte Carlo, decision rules, and references - Worked examples that reproduce published results: EA-4/02 S2 (10 kg weight, U = 59 mg) and GUM Annex H.1 (gauge block, νeff = 16, k = 2.92) PRIVATE BY DESIGN Everything is calculated and stored on the device. No account, no subscription, no ads, no analytics, no tracking. Uncertia supports transparent GUM-style calculations and review. Confirm the measurement model, correlations, distributions, sensitivity coefficients, degrees of freedom, traceability, decision rules, and reporting requirements with your laboratory procedure.

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Uncertia 2.0 is a full rebuild of the calculation engine and the app. - Budget library: keep any number of budgets, duplicate them, and start from worked examples (EA-4/02 S2 weight calibration, GUM H.1 gauge block) - Student-t coverage factor: k = t_p(νeff) for 68.27 % to 99.73 %, or keep a fixed k - Type A from raw readings: paste readings to get the mean, s, s/√n, and ν = n − 1 - More Type B options: U-shaped and certificate-k distributions, and degrees of freedom from the reliability of a bound - Correlated inputs with a consistency check - Monte Carlo check of the GUM interval (JCGM 101) - Conformity decisions with simple or guarded acceptance (ILAC-G8), probability of conformity, and TUR - Results reported with two significant digits as recommended by the GUM - New PDF report and CSV table, plus backup and restore files - A written method guide replaces the old image library - Removed the extra workbench bar that sat above the tabs - Fixed dark mode contrast, truncated titles, and missing degrees-of-freedom editing - Budgets from 1.x move into the library automatically and keep their fixed k

Version 2.0

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    Information

    Seller
    Robert Corbin
    Size
    3.8 MB
    Category
    Developer Tools
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English
    Age Rating
    4+
    Copyright
    © 2026 Robert Corbin
  • Developer Website
  • Privacy Policy

    • Supports

    • Family Sharing

      Up to six family members can use this app with Family Sharing enabled.

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