Child pages (Children Display) |
---|
Hardware
235-165-ND: FP 07 FAST TIP PROBE, 150 Kohm, at 25C
AAS-920-267D-Thermometrics-NTC-TypeFP07-041216-web.pdf
self-heating is 1C per 50 uW of power dissipation. Resistance is 150K at room temperature. Still-air thermal time constant is 100 msec.
plot of temperature increase vs. applied voltage across thermistor:
The problem with self-heating is that we are increasingly sensitive to local windspeed rather than temperature. We definitely don't want to exceed one volt across one thermistor, or 2 volts across both of them.
Paper on thermal time constant measurements in still and moving air: [15200426 - Journal of Atmospheric and Oceanic Technology] Time Constant Estimates for Radiosonde Temperature Sensors.pdf
Current stage: taking long series of data (eg a few days) to a local db to get a sense of noise, frequency characteristics