Tuner calibration

Kinya,

I have been trying to dig deeper my thought for two hours (my brain is giving off smoke ;-)).
I saw again the user guide of the Strobosoft tuner by Peterson. If I understand well, the calibration is relating to the correction of the input and it has nothing to do with the fact that I set the concert A for 442,0 Hz. In Strobosoft we don't have the possibility to refer to a specific note but to a specific frequency instead.
So what is the good procedure to calibrate the tuner? Do I have to set the frequency for 442 Hz and blow hole 4 of my A harp or isn't it better to set any frequency and this frequency with an electronic pitch pipe?
Since I have the Strobosoft Deluxe tuner, don't you think that it's better to use it with my HT rather than Cleartune?

Thanks.

Eddy