Some other points to consider if things don't go well after the first run:
1. Ensure the accelerometer is pointing in the correct direction.
2. Ensure the accelerometer is connected to the proper input channel of the system being used.
3. Ensure you have properly identified the blade ID.
The above issues are the traps most people experience most often with most portable systems.
Most likely, a gram scale in one gram increments will work well for a B47 as you aren't adding wieght at the blade tips.
Best of luck