Calculation sequence
Step-by-step method
- Confirm the measurement boundary, time basis, and formula symbols.
- Apply the displayed equation to the user-entered values.
- Review data quality, uncertainty, project criteria, and professional disposition.
CommissioningIntermediateAcceptance Arithmetic
Multi-Point Tolerance Evaluation Calculator
Calculate three signed deviations, worst deviation, and count within a visible user-entered tolerance.
Why it matters: Transparent data reduction keeps raw values, criteria, symbols, and arithmetic available for review.
Calculated result
Engineering evaluation
Worst signed deviation (δ_w)12 %
- Points within entered tolerance (N_p)
- 2 of 3
- Maximum absolute deviation (|δ|_max)
- 12 %
Engineering interpretation
2 of 3 entered measurements are within the visible ±10% criterion. Equal maximum magnitudes are reported with the algebraically larger signed deviation so the result is independent of input order.
Important limitations
- At least one entered point is outside the visible user-entered tolerance; confirm the authorized criterion and measurement uncertainty before disposition.
Engineering knowledge center
Understand the calculation—not just the answer
Governing relationships
δ_i=100(M_i−T)/|T|
|δ|_max=max(|δ_i|)
equal magnitudes report the algebraically larger signed deviation
displayed symbols: C, M_1, M_2, M_3, δ_w, N_p
Current substitution
δ=[0, 2, 12]%; δ_w=12%; N_p=2.
Equation legend
Inputs and calculated quantities
- T
- Target value — selected units
- C
- User-entered tolerance — ±%
- M_1
- Measured point 1 — selected units
- M_2
- Measured point 2 — selected units
- M_3
- Measured point 3 — selected units
- δ_w
- Worst signed deviation — %
- N_p
- Points within entered tolerance — of 3
- |δ|_max
- Maximum absolute deviation — %
Applications
How this calculation is used
Building design
Prepare a visible analytical basis for a planned test or monitoring point.
Construction
Reduce startup, TAB, controls, and field-observation data consistently.
Commissioning
Evaluate recorded measurements without hiding project criteria or uncertainty assumptions.
Quality controls
Assumptions and limitations
Assumptions
- Entered observations describe a common measurement boundary and compatible units.
- Sampling, timestamps, instruments, and user-entered criteria are documented outside the arithmetic.
Limitations
- The calculation does not create an acceptance criterion, uncertainty budget, or engineering disposition.
- Project requirements, procedures, calibration, data quality, and authorized judgment remain controlling.
Field use
Verification procedure
- Confirm the test boundary, sampling interval, units, and raw-data source.
- Enter the recorded values and any authorized user-supplied criterion.
- Review the arithmetic with uncertainty, procedure, and project requirements before disposition.
Common engineering mistakes
- Combining unsynchronized values or incompatible measurement boundaries.
- Ignoring resolution, uncertainty, sample selection, missing data, clock offset, or test conditions.
Technical basis
References and source standards
- NIST Measurement and SI ResourcesMeasurement traceability, units, and uncertainty context.
- ASHRAE Guideline 0 and Commissioning ResourcesCommissioning-process and verification context; project requirements remain controlling.
- AABC Commissioning GroupCommissioning practice and field-verification context.
Engineering calculation disclaimer
These engineering tools are provided for educational, preliminary evaluation, field verification, and commissioning support. Results depend on the accuracy of user-entered information and the assumptions stated for each calculation. Every colored status and comparison is a screening indicator only; project criteria, contract requirements, applicable codes, manufacturer instructions, measurement uncertainty, and authorized engineering judgment govern. The tools do not replace project-specific engineering analysis or the judgment of a licensed professional engineer.
Read the full use and limitation statement