Gas analyzer unlocking in The Netherlands?

[banpei]

What I could find is that the Sun analyser used to be a popular brand in the Netherlands but according to some sources they fell out of favor for high cost for yearly servicing and calibrations. I found a few other people who got a unit privately and complaining about your issue as well. The complaint is that the official dealers don't want to service privately owned ones and that after a year they lock up again.

I think your best bet would be to contact that Marktplaats guy: he seems to have means to service, calibrate and unlock these machines.