Data Logged in FRAM
The TV2 is fully 21 CFR 11 compliant. Each temperature sample is logged in FRAM. This is a type of memory that will never lose its value, even if power is removed. Logged data can't be altered in any way by the user. It can be erased, but not changed.
Password-Protected Settings
The time and temperature display parameters can be changed if the user has the proper password, but the underlying data can't be altered. Because it's stored in FRAM, the data is protected even if power is lost. You can turn the TV2 off, run the battery all the way down, walk away and come back 2 years later, and your data will still be there.
Viewing Data in TView
When the collected data is downloaded to a computer, the TView program displays it as a chart. Charts from multiple TV2s can be combined. Data from one sensor can be moved to the chart of another sensor or deleted from a chart, and data from all sensors on one or more TV2 monitors can be seen on one chart. Charts can also be printed.
Encrypted When Saved
The key point is that the data can only be viewed and moved around. It can't be edited in any way. Even when the data is saved on the local computer it can't be edited: the file can be opened, but it will appear as nonsense. The data is encrypted when it's stored, which ensures it's unaltered from the moment it's logged, meeting 21 CFR 11 standards.
Exported Data Is Not Secure
There is a way to edit the data, but it breaks the 21 CFR 11 rules. Charts can be exported to an XLS file that can be opened in Excel, so if you don't need to keep secure data, you can load a previously saved TXV file onto your computer and export it. Whenever a file with a TXV suffix is loaded into the TView program, a small icon appears on the screen to show that you're viewing encrypted data.
If exported data is loaded into Excel, Word, Notepad or another text editor, it can be changed and re-saved, but it can't be loaded back into TView. Once that happens it no longer meets the requirements of US regulation 21 CFR Part 11. As long as the data is in a TXV file, it's encrypted and complies with 21 CFR 11.
Temperature history chart downloaded to a computer.