Pete:
It is not necessary to check for occasional lost impulses with the Protege, because, except for the cases I mention below, they never occur.(All or no impulses are recorded.) One impulse is always lost in the following cases:
1. A ride of half a marathon without rezeroing.(Does not apply to the two-magnet method.)
2. The wheel is stopped for five minutes and is started again without first waking the computer.
3. Rezeroing is done with the wheel slightly ahead of the zero point. (Also does not apply to the two-magnet method.)
However, if many stops are made during measurement, it is possible through carelessness and bad luck to stop on the wheel zero point and roll back to generate one or two spurious impulses.(Using two computers simultaneously might detect these immediately.) Postcal is of no value in detecting these, but they are readily detected if at least one ride is made over the course with few or no stops.(Riding continuously between marking splits would be equivalent to the latter.)