Content update (Andrea's review)

Author: canchebagur

content/hardware/07.opta/opta-family/opta/datasheet/datasheet.md

@@ -541,7 +541,9 @@ Now that you have gone through the basics of what you can do with the device, yo
 
 ## Mean Time Between Failure (MTBF)
 
-MTBF, which stands for Mean Time Between Failure, is calculated according to statistical device failures and indicates the reliability of a device. **Important note**: MTBF is the statistical representation of the likelihood of a unit failing and _does not necessarily represent a product's life_. The MTBF figure (in hours) for each Arduino Opta® variant can be found in the following table: 
+MTBF, which stands for Mean Time Between Failure, is calculated according to statistical device failures and indicates the reliability of a device. **Important note**: MTBF is the statistical representation of the likelihood of a unit failing and _does not necessarily represent a product's life_. 
+
+The MTBF figure (in hours) for each Arduino Opta® variant can be found in the table below. The MTBF figure was calculated according to the MIL-HDBK-217F parts count method.
 
 |      **Standard**      |   **Opta® Lite**   |   **Opta® RS485**  |    **Opta® WiFi**    |         **Environmental Conditions**         |
 |:----------------------:|:------------------:|:------------------:|:--------------------:|:--------------------------------------------:|