In certain instances, once the heat sink requirements for a SSR in a particular application have been determined and installed, (see the Crydom paper entitled SELECtING A SUITBLE HEATSINK), it may be desirable to verify that the system does indeed provide adequate cooling to ensure reliable SSR operation. The following is a relatively simple method to check this suitability, and essentially uses some of the calculations from SELECTING A SUITABLE HEAT SINK in a reverse manner. This technique may also be used on existing systems in the field that might have been more or less “empirically” designed, to gain information on their performance and potential reliabilty. This method involves determining the temperature of the internal power devices, (SCR’s or Triac), within the SSR and then comparing that temperature with a “standard” absolute maximum temperature that the SSR power devices must never exceed. The maxium power device temperature is generally considered to be 125°C but for an added safety margin, 115°C should be used. (Of course for the truest indication, the entire system being evaluated should be stable and operating at its maximum rated parameters including load currents, ambient temperatures, and with doors and access panels in their normal operating positions.)