The HP E1938A OCXO that I worked on had a feature where we could set the oven temperature individually on each oscillator to the exact turnover point of the crystal. With all the temperature characterization we did, it would seem like if there were a thermistor "aging" process, we would have seen it. However, we didn't have the resources to proactively search for it. The E1938A oven is stable to a fraction of a milliKelvin, over its rated -55 to +85 degree C spec. We used three thermistors and averaged them. They were basically the same thermistors used in the 10811. IIRC, we bought them from Yellow Springs.
Rick N6RK On 9/26/2020 1:23 PM, John Ponsonby wrote:
Have any time-nuts got any data on the long term stability or drift rates/ageing characteristics of thermistors? I am concerned with ability of holding temperature constant at the milliK level for years. I reckon that if one can measure it one can control it. Conversely if one can't measure it, because of the instability of the sensor, one can't control it. John Ponsonby _______________________________________________ time-nuts mailing list -- time-nuts@lists.febo.com To unsubscribe, go to http://lists.febo.com/mailman/listinfo/time-nuts_lists.febo.com and follow the instructions there.
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