As the individual resistive elements of ACAS AT series components are thermally coupled by the shared alumina substrate, even heat distribution across the entire resistor array is achieved. For resistors, the temperature of the resistive element determines the magnitude of resistive drift over time. Due to this inherent thermal coupling, the resistors of the array will drift together at virtually the same rate even under different load conditions. Consequently, the relative resistive drift of the ACAS AT array's resistance ratio is extremely low, specified at a maximum of ±0.05% after 1000 h considering the standard power operation mode power rating, and is typically much smaller.