Full definition
Threshold value of a condition parameter indicating deterioration that requires action. Two levels are set: Alert (yellow) — increase monitoring frequency, plan intervention; Danger (red) — stop or intervene immediately. For vibration (ISO 10816): process machinery <15 kW, alert at 4.5 mm/s, danger at 7.1 mm/s. For bearing temperature: alert at ΔT +20°C above baseline, danger at ΔT +40°C. Levels are determined from baseline measurement plus statistical history of the specific machine.