You can connect your APPA 109N (107N) multimeter(s) to PC using appropriate USB/RS232 optical adapter cable. The units can acquire the actual reading and calculate the corresponding uncertainty.
The software has been tested for errors, stability and speed (bugs free is not guaranteed, see the licence).
The uncertainty of the measurement is a sum of it's random and systematic part. It is defined by the manufacturer and described in the manual as follows:
uncertainty = n% * reading + N * resolution
If we measure a one separate value - it's full uncertainty (3 sigma, 100% confidence interval) will be the sum of both parts.
Linux, Windows
You can change the multimeter modes directly on the multimeter. Software just reads the data and have no control over the device.
If the multimeter is switched off by itself (power saving, 45 min) the program will ask you to switch it on. If you want the multimeter to run forever (without auto switch off) just switch it on while holding the blue button.
For reporting bugs, suggestions, patches
The project is licensed under the MIT license