The fundamental difference compared to a regular NANO is that the NANO SD has 2 GB of permanent storage while the NANO just has 16 MB onboard flash mostly covered by the operating system and the application programs. Equipped with 2 GB the NANO SD can hold about 20 years of data. NANO SD holds data for last 72 hours in a per minute resolution and older data in a per hour resolution. Hourly data can be inspected and edited through the NANO web interface. So it just needs a few clicks to select a sensor and the year, month and day to inspect. Data can be changed by simply clicking onto the corresponding value in the table at the bottom. When you change a value on per hour level, the changes will also be propagated to affected data of the day, month and year automatically. This makes handling of logged data rather intuitive and you don't need separate tools for it.
NANO SD also allows to export data of user-defined time frames in various time resolutions. Specification of year, month, day is done in the upper part first. Then you can select a template that defines the structure of the export in the middle part. By pressing one of the export buttons a CSV data export is generated in the export folder of the microSD card. To transfer this data to your PC for follow-up processing or archiving you don't have to move the microSD card, but simply mount the NANO SD as a PC network share. This works natively on PC, Mac or Linux clients. That way the data store of the NANO can be used by all computers in your home network.
The NANO SD can generate powerful interactive charts based on the data stored locally. All you need to do is to select a chart type and time period to inspect and a time resolution. Having done so it just takes a few seconds for the chart to show up. When you move the cursor into the chart area a vertical ruler provides information about the point in time selected and data boxes for all sensors will show numerical data. Furthermore, you can customize the charts by clicking onto the sensors. This will activate or deactivate display of the touched sensor. The handles at time line's start and end can be moved to zoom in to areas that need further inspection.
Data export and chart generation are based on templates stored in the template folder of your NANO SD. Therefore, the output format is not hard coded but can be adapted to your needs.
Many more details on the NANO SD can be found on the Meteobridge web page here.