I recently measured the operating (baseplate) temperatures of several different rubidium standards. These are all in free air without heatsinks. Results are as follows (degrees C over ambient, warmest point found on device):
FRK-L: +21C M100: +18C LPRO: +24C 5650A: +35C PTB100: +12C The FRK-L mounted on a heatsink with around 80 square inches of heatsink fins had a 11C rise. The fins were in contact with a table, with the device pointing up. The LPRO was operated with the baseplate in a vertical orientation at 24V. The FRK and M100 with the baseplate in contact with a table at 27V. The 5650A was operated at 15V with the baseplate vertical. The PTB-100 is essentially an FRK-H with a heatsink that is mounted in a Tektronix TM-500 module. It appears all the devices can be safely operated in a room temperature environment without heat sinks, but for highest reliability and longest life one should provide some form of heat control. The FRK/M100/LPRO would probably be fine with their baseplates secured to a metal chassis. The FEI-5650A is very close to its maximum specified operating temperature (65C). It would probably exceed the spec if enclosed in a case without airflow. Just a little moving air goes a long way to keeping things cool. Passive cooling with just a heatsink tends to be rather ineffective. _________________________________________________________________ It’s easy to add contacts from Facebook and other social sites through Windows Live™ Messenger. Learn how. https://www.invite2messenger.net/im/?source=TXT_EML_WLH_LearnHow _______________________________________________ time-nuts mailing list -- time-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/time-nuts and follow the instructions there.
