@Edent interesting, I don't think mine can be calibrated. Then again they're cheap and the batteries don't last well so they don't do much for me at all (should probably try some LiIon AA tbf)
Oct 11, 2026, 3:03 PM@sldrant by calibrate, I mean checking it goes from 0 to 100 and back again 😄
@Edent @sldrant From conversations with some soil scientists, years ago, soil moisture sensors are deeply unreliable -- even the good ones tend to drift (a lot) in their calibration over time.
Someone at Southampton was trying to develop ones using thin-film techniques, which drifted even more, but were a lot cheaper, so you could replace them more easily.
@Edent tbf I'm not sure mine do much from 0 to 50, but even having them reliably keep power so I get notified to water when dry would be great. Have had mine years and never got around to properly utilising them