Pyle HRM

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Anybody have one? I have a 38R and can't get it to read correctly. It has my HR all over the place, from 232 to 72 during Pure Cardio and you know the 72 is off, cause even resting, my HR is almost 80. I've programmed in my age, weight, and VO2 Max, but can't figure out where the calories burned count is. If it's the number I thought it was, it said 222, but then I think that was the max hr, then today it said 172 and again, not sure what that number was. Then there's the Kcal, and one number said 7, then it said 91.