THE RESULT
What the data shows
The largest computed metric is 8,126 for nmhc_gt; the smallest is 76 for pt08_s1_co. Metric: longest_missing_hours (Consecutive hours).
This measures unavailable readings, not a verified device outage cause.
| field | missing hours | longest missing hours |
|---|---|---|
| co_gt | 1,683 | 173 |
| nmhc_gt | 8,443 | 8,126 |
| nox_gt | 1,639 | 173 |
| no2_gt | 1,642 | 173 |
| pt08_s1_co | 366 | 76 |
| pt08_s2_nmhc | 366 | 76 |
| pt08_s3_nox | 366 | 76 |
| pt08_s4_no2 | 366 | 76 |
| pt08_s5_o3 | 366 | 76 |
THE METHOD
From source to answer
Complete hourly timeline and consecutive missing-run lengths.
The Python source exposes this study’s transformations. The complete project download includes shared preparation and evaluation routines.
THE NEXT DECISION
What follows from the finding
Distinguish short intermittent gaps from extended periods unsuitable for calibration.
Where the conclusion stops
The -200 sentinel is treated as missing. Reference instruments have incomplete coverage; comparisons use paired observations. Sensor calibration is retrospective, not a health or regulatory compliance assessment.
Related studies may reuse observations or holdouts. These are historical analyses; associations and backtests do not demonstrate commercial impact. Further model tuning needs new, untouched evaluation data.