Cardio Intensity

I know this issue comes up alot, but how intense is low intensity cardio? I've started doing fasted state cardio on a treadmill with no heart rate monitor (frankly I don't trust the machine monitors anyway), and don't really huff and puff, just break a bit of a sweat. Basically I set the treadmill at a brisk walking pace with a slight incline. Does that sound right?

I like 70% of your MHR. I dont trust them either, but that is what I go by. Today, I was going pretty good it said my HR never got above 132, which is bullshit. Before, I could get it to 132 by doing elliptical at level2 at 55rpm. Today, I was doing level5 at 65rpm.