Hello kmgary
Sampling rate is 50 kHz, thus this mean fmax=20kHz?
If fmax=20kHz and you have 3200lines the resolution is 6Hz, this is 180/min, so your first line is 180/min, the second 360/min , you will have only 15 significant lines for an run-up 0-3000/min, this looks no good.
Good luck.
DePauw
Hello Ksener
I think looseness is the problem.
You chech it like this : put a clock-meter ( 0.01mm) on the axis and lift the ventilator with a jack, 0.05 mm is normal, 0.1 mm is still good, 0.2mm or more is bad.
Good luck
DePauw
Hello kmgary
First to know is the total run-up time.
Then you divide it in +- 20 to 50 pieces
In each part you take a mesurement, attention there is a relation between number of lines, max freq and sampling time.
The problem is the FFT, this algoritme thinks that the speed is constant so it...