The power rating of RCM series resistors ranges from 0.125 W up to 2 W at ambient temperature up to +70ºC for RCMM, RCMA, RCMT, and RCMS models, and +85ºC for model RCME. The power must derate beyond this temperature according to the power derating curves shown here. Typically, this means that the voltage across the resistor must be reduced to keep the power under the maximum specified rating in the de-rating curve. For example, according to Ohm’s law, for model RCMM1, which is rated up to 1 W at +70ºC, the maximum voltage that can be applied to a 10 kΩ resistor is 100 V up to +70ºC ambient temperature. This voltage must be reduced to no more than 59.16 V to reduce the applied power to 35% of 1 W at +125ºC, according to the power de-rating curve.