Depending on the model, the "Saveris 2" systems monitor temperature or humidity at regular intervals and store the data for later analysis in the cloud. If thresholds are violated, the systems also send alarms via e-mail or SMS. For example, users can use the data loggers to monitor the climate in workrooms, museums or warehouses, to query and document them from any location via the Internet.
For our test, we looked at the model Saveris 2-T3. Testo supplies the data logger intended for stationary use completely - including batteries, USB cable and lock-secured wall mount.
The format of 95 x 75 x 30.5 millimeters is reminiscent of a cigarette packet that is a little too big, but with 240 grams the system is much heavier - the four AA batteries included are already included. The battery cover on the back of the solid-looking and IP54-protected Saveris 2 is secured with two screws. At the front there is a status LED, an LC display and a membrane switch - to synchronize the device immediately with the cloud and not wait for the next communication cycle. At the bottom there is a capped micro USB port - through which the device is configured and alternatively powered.There are also two protected connections for thermocouple sensors (TE) at the bottom. These are not included and must be purchased separately. This means additional expenditure, but makes the device extremely flexible: There are a variety of air sensors, pipe fitting sensor or self-adhesive film sensor. Depending on the sensor, the Saveris 2-T3 covers a measuring range between -195 ° C and +1350 ° C. For our experiments, we opted for a comparatively inexpensive jacket thermocouple with miniature plugs (type K, yellow, Ø 1.0 mm, NL100) from B + B Thermo-Technik GmbH.
Facility
To set up the Saveris 2 you need a PC with internet connection. New users largely navigate the Saveris website through the installation process, creating a configuration file as well. The XML file is transferred via USB to the Saveris and provides it with the cloud key as well as the access data for the local WLAN. Connected to the network, our Saveris was initially automatically supplied with a firmware update.
Once set up, the configuration file disappears from the file system of the Saveris 2. It is therefore advisable to save the self-explanatory file for later customization. Incidentally, the Saveris 2 can only dial into a WLAN: The solution is not designed for mobile applications with changing access points.
Cloud is required
The Saveris 2 can also operate temporarily without a network connection: In the internal memory, the solution can store 10,000 readings per channel. The LC display not only informs about battery and network status, but also displays the currently measured temperature values and warnings. However, the hardware does not offer more utility than a better thermometer until it interacts with the web-based analysis solution.
The dashboard is designed for multiple data loggers and users. The systems can be named and organized in areas or measuring point groups. Users can assign different data loggers to different buildings or rooms.
In addition, different users can share access to the web interface. Corresponding user roles are predefined and can read or write access to the collected data. However, additional users must be entered manually and also be informed manually about their credentials - the system does not automatically provide new users with their login data.
Communication clock and energy demand
How extensively the wireless data loggers collect data depends on the license model and configuration. Technically, the systems can measure temperatures every minute and forward them to the cloud. Measurement and communication cycles can be selected in minutes for up to one hour, then it continues in full hours - measured and communicated daily at least once.
