Ah interesting. I have a weather station that uses that chip (not sure if 40 or 45), and the instructions say to never expect great information from it until y

Ah interesting. I have a weather station that uses that chip (not sure if 40 or 45), and the instructions say to never expect great information from it until you calibrate it against a sling psychrometer. (It is certainly not the worst humidity sensor I have. The one in my humidifier is consistently 10% off from the other sensors. The BME280 seems to yield similar results to the SHT45. But without a calibrated reference, I'm just guessing, and assumed that was the state of the art of electronic humidity sensing. A man with two inaccurate watches that agree with each other is never on time, or something like that.)