No, I’m not sure. And I think that you’re right in pointing that actually it was 2 min and 49 sec.
Nevertheless, the scheduled time was 30 sec. Also allowing a plus for the Zimmermann method I would expect a figure round 33 seconds
(30(sec) * 1.08 (%) = 33 sec)
It seems that seconds are considered on base 10, instead than on base 60.
I see that the other channel (1 min scheduled time) with a correction of 108% results into a 1 min + 8 sec
Is that right ?