# Trouble Shooting 

## Sensors

### Battery replacement

A battery replacement does not require a change to the digital twin. Data should automatically start streaming again and the models will adjust over time.

### Sensor replacement

If a sensor is replaced by a new sensor, the new sensor needs to be linked with the station. To do so, follow these steps:

1. Select the station either in the station summary or on the map
2. Go to the Sensor Quality section
3. In the drop-down menu select the new sensor

Note that it will take 24 hours for the new sensor to show up in the station summary. 

After the new sensor has been selected no further action is required. The models will automatically adjust over time.

## Adding or removing a station

To add new stations or remove existing stations, please contact the SIMPaCT team.

## Calibration

### NSE below 0.5

If the calibration quality is below 0.6, the sensor will not be used for forecasting. Usually, a bad calibration quality is caused by:

- the sensor not responding to irrigation or rainfall. If the sensor is flatlining check for technical issues
- the recording period is too short. We recommend at least 2-3 months of data for a good calibration. However, it might still be possible to use the ML model since it relies on a shorter time recording period
step changes in the data recorded by the sensor. 
- step changes in the data recorded by the sensor. This might be caused by a faulty sensor or a change in its location. In this case, adjust the calibration period to exclude the step change