Predictions
How Open Gauge projects future drift, and what that has (and hasn't) got to do with calibration due dates.
Drift prediction
Open Gauge runs a linear regression on a channel's historical maximum drift values, projected forward from today. This gives a rough answer to "if this trend continues, when might this sensor's drift become a problem?" — useful for planning, not a certified forecast.
Recommended interval vs. the certificate
The recommended interval shown on the Health tab is an Open Gauge-internal planning heuristic. It is never printed on a calibration certificate — see Certificate generation for why ISO/IEC 17025 requires an explicit customer agreement before a certificate can state an interval recommendation.
Requires at least two calibrations
Every prediction and drift metric on this page needs at least two calibrations on a channel to compute anything meaningful — a single calibration has no history to fit a trend against. Until then, Open Gauge shows a neutral 100% health score, "Stable" stability, and 0 drift rate rather than a number computed from insufficient data.