Load-cell measurement chain

Implementation

Seeded six-point calibration with slope/intercept covariance

Six causal filter variants, step settling, systematic drift and uncertainty budget

Optional explicitly gated zero tracker with sustained-load tests

Executed synthetic/theoretical validation with a selected operating envelope, adverse conditions, and reproducible acceptance evidence.

Inputs and assumptions

• 10 kg bridge, 2 mV/V sensitivity, 5 V excitation; reference 24-bit ADC with 2.5 V reference and gain 128
• 100 Hz acquisition; 2 µV RMS independent white noise; positive 0.02 g/s drift; every trace and calibration sample is synthetic
• Residual nonlinearity ±2 g, hysteresis ±1 g, temperature-zero ±1.5 g, temperature-span ±0.01% of reading over 10 °C; these are assumed uncertainty bounds

Results

Report figures (4)

Open the full report ↗

Verification

18 tests; exact calibration, Monte Carlo covariance, causal filters, analytic settling and drift preservation. Additional virtual validation: 12 checks matched their expected outcomes. Adverse design conditions remain in the results.

python run.py

Project files

The ZIP contains the source, inputs, results, and instructions. These files are also available individually.

• Analysis reportreport.html · 9 KB
• Calibration, filters and zero trackermeasurement.py · 5 KB
• Reference and synthetic-data inputsinputs.json · 1 KB
• Generated calibration readingsdata/synthetic_calibration.csv · 13 KB
• Uncertainty budgetresults/uncertainty_budget.csv · 1 KB
• Filter comparisonresults/filter_comparison.csv · 1 KB
• Verification casestest_measurement.py · 4 KB
• Unexecuted physical calibration procedurephysical_calibration.md · 2 KB
• Virtual validation reportvirtual-validation.html · 12 KB
• Completion evidence and source hashescompletion.json · 6 KB
• Reproducible virtual validationvirtual_commissioning.py · 15 KB
• Executed acceptance matrixresults/virtual-acceptance.csv · 2 KB
• Selected measurement envelopeselected-operating-envelope.json · 1 KB
• 16 verified selected-envelope cornersresults/virtual-selected-envelope.csv · 1 KB
• Thermal screening and synthetic interference after samplingfigures/virtual-instrument.svg · 39 KB
• All 24 temperature/load cornersresults/virtual-temperature-corners.csv · 2 KB
• Calibration contamination casesresults/virtual-calibration-rejection.csv · 1 KB
• Correlated uncertainty calculationresults/virtual-correlated-uncertainty.json · 1 KB
• Analog filtering and aliasingresults/virtual-aliasing-summary.csv · 1 KB
• Synthetic interference traceresults/virtual-aliasing-trace.csv · 34 KB

Run locally

Python 3.11+ / NumPy / Matplotlib

Extract the ZIP and open a terminal in the load-cell-measurement folder. The README includes setup and usage details.

python -m pip install -r requirements.txt
python run.py
python -m unittest -v

Limits

• No physical bridge, ADC board or calibration masses were measured. These results validate the analysis code under stated synthetic conditions.
• Differential ADC headroom is calculated; common-mode input range, excitation/reference tracking, analog anti-alias filtering, EMI, mounting and overload survival need actual component and installation checks.
• The baseline budget assumes independent components except for fitted slope/intercept covariance. The separate virtual-validation report also evaluates shared temperature error; its expanded uncertainty is higher.
• k = 2 is an illustrative expanded uncertainty, not a certified 95% coverage claim. The Type B bounds must be replaced by evidence before using the budget for acceptance.
• Zero tracking is disabled in the reported measurements. The optional tracker requires external empty-pan confirmation; it cannot distinguish drift from a small real load if that confirmation is wrong.