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Member #144947

Member Since: August 2, 2010

Country: United States

  • I have been using this sensor for about 3 months. The a/d converter is 1024 counts for full scale (3.3V) and I calibrated by taking a sample of my garden soil, weighing it dry then adding water to saturation. As the soil dried, I weighed the container and recorded the adc counts and the weight. I found that the sensor output curve flattens at low water values and high water values but is pretty linear in the range 800 - 880 counts (2.6 - 2.8 ).

    In the Garden, the probe is powered only a few microseconds once each minute so I have not observed any corrosion issues.

    From observation, it appears that the sensor output is also dependent on temperature (lower voltage for cool temperature; higher for warm). Consequently my garden generally gets watered near dawn when the temperature is lowest.

    Has anyone else noticed this dependency? or have any temperature data?

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