I have a very sensitive scale used for dynamic weighing (by dynamic I mean that the scale and load cells are actually beneath a belt conveyor that actively weight product when it´s being transported along the belt).
There´s a lot of variation in the measurements (+- 8g, while the manufacturer says it should be max +-2g).
I want to rule out vibration as a source of enviromental influence, so I gathered some data with a pair of 3 axis accelerometer dataloggers mounted on the structure beneath the load cells.
I analyzed the data in Matlab and found that the maximum vibration frequency when the equipment is being static is 1.066 Hz (EDIT 3); peaks of 1.33 g in the z axis (perpendicular to the floor).
It´s being a while since I´ve done anything with vibrations and I´m a little rusty on the theory and practical experiments.
I´m not sure what I should be looking for and I don´t have (didn´t find) anything about what the normal structural vibrations are for a lab room or specifications from the scale manufacturer on how much vibrations in can withstand or filter out.
I´d appreciate any suggestions.
The Scale is installed on top of a mezanine 5m tall. The Accelerometer specifications are: Sensor Type MEMS semiconductor Acceleration Sampling Rate (Datalogger) 200Hz Acceleration Range ±18g Acceleration Resolution 0.00625g Acceleration Accuracy ±0.5g Bandwidth 0 to 60Hz Sampling rate (Software) 500 ms to 24 hours Memory 4Mbit Flash; 112028 Motion Detection samples per axis, or 168042 Normal samples Data Format Time stamped peak acceleration, average and peak vector sum Dimensions 3.7 x 1.1 x 0.8" (95 x 28 x 21mm) Weight 1oz (20g)
The FFT results in the X,Y and Z axis were: