The amount of moisture in air expressed as a percentage of the maximum moisture the air can hold at that temperature. 100% RH = saturation (condensation begins).
Temperature Cycling
Repeated temperature fluctuations above and below the target temperature range. Can be caused by poor equipment control, door openings, or system cycling.
Temperature Differential (Pull-Down Time)
The time required to reduce product temperature from initial temperature to target storage temperature. Also called “cool-down time” or “freeze-down time.”
Temperature Excursion
An event where product temperature moves outside the specified acceptable range. Must be documented and investigated per R638 and GDP requirements.
Temperature Gradient
Temperature variation within a refrigerated space or vehicle, typically measured as the difference between warmest and coldest locations.
Temperature Mapping
Systematic process of measuring temperature at multiple locations within a refrigerated space over time to identify temperature gradients, hotspots, and system performance.
Temperature Profile
Graphical representation of temperature over time, showing fluctuations, excursions, defrost cycles, and door openings. Generated by data loggers and monitoring systems.
Temperature Uniformity
Consistency of temperature throughout a refrigerated space. High uniformity means minimal temperature gradient; low uniformity indicates significant temperature variation.
Thermal Shock
Rapid temperature change that can damage products, packaging, or equipment. Occurs when cold products are exposed to warm environments or vice versa.