Personal HRM vs HRM on machines

AakifahSiebert

I bought a HRM a month or so ago...it's a little watch that's supposed to monitors my heart rate, calories, ec. The elliptical at the gym also tracks heart rate and calories....but, I get different readings on the HRM I bought vs what the elliptical shows (and they are VERY different readings). I do input my weight and age in the elliptical machine when I use it. When I do the elliptical for 30 minutes, on average I burn about 330 cals (according to the machine), but according to my HRM, it'll say on average 150 cals (also, I should note that often, about ten min into my exercise, it no longer registers my heart rate...Idk why). So,....my q is...which is more accurate you think....the machine or my HRM I bought?

Also, I use my HRM when I jump rope for ten minutes....however, it shows i barely burn any calories when I jump rope. In fact...if I walked ten minutes vs jupm rope for ten minutes, it shows I burned more from walking, but i somehow doubt that is correct.