Hello, 2 months ago I bought the ember, to know my hemoglobin, the first thing was to verify with a first laboratory analysis, and the value was verified perfectly. in the last two months I took measurements when I got up and when I went to bed. I started to see that it had a very big difference, in general around 13 in the morning and from 15 to 16 in the evening, the busy journals around 17. Yesterday I checked it again and at the same time the ember dialed 13.4 and the laboratory 14.8, what experience have you had with the ember? Did someone take it tomorrow and night? Thank you.

Hemoglobin levels vary during the day within the same person. Hgb levels are always higher during the morning and lower at evening. The difference between the highest and lowest levels during the day can be a slight difference but it can reach as much as 1 gram per deciliter.  This has to do with differences in hydration levels and also with changes in elevation -- for those that commute between low and higher elevation areas. 

I too am disappointed in the Ember, because I can get different numbers at the same time depending on which fingernail I use to take the measurement.  However, if I stick to the ring finger, as recommended by the manufacturer, I get the most reliable reading -- meaning, the one closest to what I would get from the HemoCue analyzer or from laboratory results using venal blood.  My conclusion is that the Ember is probably good for a quick assessment between results within the normal range and results way above or way below the normal range. I don't know for sure because I haven't experienced results way above or below the nomal range since purchasing the Ember.  Just in case, I carry the Ember with me whenever I leave home for some other overnight destination.