# Soil moisture Soil moisture sensor shows values in the range between -200kPa and 0kPa. Efento soil moisture sensors come pre-calibrated and the initial calibration is not required. However, during the operations the accuracy may decrease and recalibration may be required. Recalibration can be performed by the user. In order to calibrate the sensor, place the soil moisture probe in a vessel with water, so that it is completely submerged. If the sensor shows values other than 0kPa, calibrate it by setting the value of “Measure offset” to 0 kPa. This process can be done using a mobile application. Connect to the sensor -> settings (three dots in the upper right corner -> “Advanced” -> “Calibration” -> “Calibration parameters” -> “Select a channel” -> “Measurement offset”. {% hint style="info" %} **Important! Wet soil moisture probe should read 0kPa**- **Dry soil moisture probe should read -200kPa (it takes up to 24 hours for the probe to dry completely)** {% endhint %} --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.efento.io/nb-iot-loggers/sensor-specific-settings/soil-moisture.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.