I had to get a new peak flow meter last week and have been having real problems with consistency. When I first used the new unit (different make to the previous one) I was shocked at how high my reading came out but know that different meters can vary. When I do my three readings, it is incredibly inconsistent with readings more than 200 apart from each other. I have checked my technique and am taking the readings whilst looking in the mirror. I’ve stopped measuring my peak flow right now as it seems completely pointless with such massive variability. Has anyone else had this problem? I don’t know whether to take it back to the pharmacy as faulty, ask for a prescription for a different one or to buy one online - any suggestions?
(Photo of the new, inconsistent one)