# Soil moisture sensor

Soil moisture sensors measure values from –200 kPa to 0 kPa and are factory-calibrated, so no initial calibration is needed. Over time, accuracy may drift and recalibration may become necessary. To recalibrate, fully submerge the probe in water; if the reading differs from 0 kPa, adjust the **Measurement Offset** parameter so that the displayed value is exactly 0 kPa.

{% hint style="warning" %}
**Important!** Proper installation of the soil moisture sensor is essential for accurate measurements. Always follow the provided [installation instructions](/efento-ble-loggers/installation/logger-specific-installation-guidelines/soil-moisture-sensor-installation.md) carefully.
{% endhint %}

| Measurement Offset | Adds or subtracts an offset value to the pressure measurement result in kilopascals (kPa). | Range: -100 to 100 kPa. |
| ------------------ | ------------------------------------------------------------------------------------------ | ----------------------- |

{% hint style="info" %}
A fully wet soil moisture probe should display **0 kPa**.\
A completely dry probe should display **–200 kPa**, though full drying may take up to **24 hours**.
{% endhint %}

Important


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