We recenty sent our Respical flow/pressure tester back to Braun for calibration (We purchased it from them). Braun now inform us that it needs to be returned to Allied in the States for calibration and that Allied are closed until mid January. - Some Christmas holiday! Last year we were without this for almost 6 months whilst it was away for calibration. Presumably we are not the only department with one of these. What do you do for calibration?