That sounds good 
But you are talking about pulses, the sensor outputs a frequency, that isn´t the same?
is Pulse the time and freq the hight of the wave? And the dutycycle of the sensor is 50%, is that because it ouputs a square wave or something?
I did all the maths in the sketch last night, just to see how things work together like pulses, frequency an so forth. One thing i i stumbled upon is the "Gate time", what exactly is that, because that one is set to 100ms in the sketch, but somwhere on the internets, i read that the Gatetime should be set to 1000ms to get "the true freq of the sensor"?
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