Meaning
Temperature correction values compensate for the temperature differences that develop between a thermal sensor and a test specimen during rapid heating. Using a thermal conductivity offset adjusts the recorded temperatures to reflect the actual temperature of the sample itself. It is essential when analyzing materials with low thermal conductivity or when using fast heating rates.
Thermal Lag
During a thermal scan, heat must travel from the furnace through the sensor and sample pan into the specimen. This creates a temperature gradient where the sample temperature lags behind the measured sensor temperature, necessitating the thermal conductivity offset to align them. The size of this lag is proportional to the heating rate and the sample’s thickness.
Fast scans generate larger temperature differences across the sample holder. Neglecting this lag leads to reporting transition temperatures that are higher than their actual values.
Calibration Correction
Correcting for thermal gradients involves running calibration standards with known transition temperatures at different heating rates. By analyzing how the transition temperature shifts with rate, the operator determines the thermal conductivity offset coefficient. This value is entered into the instrument’s software to automatically adjust the raw data.
It ensures that the reported results are independent of the heating rate used.
Measurement Integrity
Inaccurate temperature readings can lead to serious errors when predicting material behavior in production environments. Applying the thermal conductivity offset prevents the misinterpretation of transition points, which are used to set curing or extrusion temperatures. This correction is particularly important in industrial settings where heating runs are optimized for throughput.
It ensures that the laboratory data matches the behavior of the material on the factory floor.
